Infections with certain viruses, bacteria, and parasites have been identified as strong risk factors for specific cancers. To examine the link between infections and cancer, researchers performed a systematic analysis of the proportion of cancer cases attributable to infection in 2008. They used data on cancer incidence from the GLOBOCAN project along with epidemiological data regarding the causal effects of infection on cancer. The data included information on 27 types of cancer from 182 countries.

They found that of the 12.7 million new cancer cases that occurred worldwide in 2008, 16 percent—or roughly two million—were attributable to infections. The rate of infection-related cancer was about three times higher in developing countries. For example, 3.3 percent of cancers in Australia and New Zealand were infection related, whereas 32.7 percent of cancers in sub-Saharan Africa were attributable to infections. The four main infections associated with cancer were human papillomavirus, hepatitis C, hepatitis B, and Helicobacter pylori. These infections were responsible for approximately 1.9 million cancer cases in 2008, mainly gastric, liver, and cervical cancers.

Cervical cancer accounted for about half of the infection-related cancers in women. Liver and gastric cancers accounted for more than 80 percent of the infection-related cancers in men.  About 30 percent of infection-related cancers occurred in people younger than 50 years. It’s important to note that it takes decades of chronic infection before an infection progresses to cancer.

Based on the statistics, the researchers noted that approximately two million cancer cases each year might be preventable with better public health methods for preventing infection. In an accompanying editorial, Dr. Goodarz Danaei, an assistant professor of global health at Harvard School of Public Medicine in Boston, noted that vaccines for HPV and hepatitis B are effective and that increasing their availability should be a priority for higher risk countries.[2] He suggests that increasing vaccine coverage could reduce the global burden of cancer.

References:

Lung cancer remains the leading cause of cancer death in the United States. Non–small cell lung cancer (NSCLC) accounts for approximately 85% of all lung cancers.

Many NSCLC cases occur in people over the age of 65, but there is limited information about how best to treat older patients coupled with concern that older patients will not be able to tolerate aggressive treatment. As a result older patients sometimes do not receive treatment that might be of benefit; for example, older patients may be treated with single-agent chemotherapy rather than the combination chemotherapy that is commonly used in younger patients.

Previous research has indicated that older patients with NSCLC who are otherwise healthy can benefit from treatment, while those with comorbidities—or other severe illnesses—are more vulnerable to the toxicity of cancer treatments and therefore less likely to tolerate and complete a course of treatment.

To examine the effects of comorbidity and age on treatment outcomes, researchers used data from the Veterans Affairs (VA) Central Cancer Registry to analyze treatment and outcomes from more than 20,000 veterans over age 65 with NSCLC. They found that regardless of stage of cancer, treatment rates decreased more in association with older age than with comorbidity.

Younger patients—those between the ages of 65 to 74—were more likely to receive treatment, regardless of comorbidity status. In other words, those who were severely ill—and thus less likely to benefit and more likely to be harmed—received treatment at approximately the same rate as patients in the same age range who were not severely ill. In contrast, older patients—those between the ages of 75 and 84—were less likely to receive treatment, even if they had no comorbidities and a better prognosis.

The researchers concluded that physicians appear to base treatment strictly on age, while overlooking other factors. A patient’s overall state of health is an important factor when determining treatment. An otherwise healthy 75-year-old may tolerate treatment well, whereas a severely ill 65-year-old may not. In short, treatment decisions must be individualized rather than based strictly on age in order to target NSCLC treatment to older patients who may benefit.

Reference:

Wang S, Wong ML, Hamilton N, et al: Impact of age and comorbidity on non-small-cell lung cancer treatment in older veterans. Journal of Clinical Oncology. 2012; 30(13): 1447-1455.

How does cancer treatment affect fertility in men?

Chemotherapy: Chemotherapy can temporarily—and in some cases, permanently—stop sperm production by the testes.[1] The extent to which chemotherapy affects sperm production depends on several factors, including the type and dose of chemotherapy.

Radiation: Radiation to the abdomen or pelvis can also reduce or eliminate sperm production by the testes.

Surgery: Surgery that involves the removal of both testicles (an option for some men with prostate cancer) eliminates sperm production, but other types of surgery can also affect a man’s fertility. Some types of pelvic surgery, for example, can change or eliminate ejaculation.

Options for preserving fertility in men

Although many men are able to conceive naturally after cancer treatment, others are not.

If possible, men should talk with their doctor about their future fertility before beginning cancer treatment. Some options for preserving fertility require that steps be taken before cancer treatment begins.

Sperm banking is the most well-established method of preserving fertility in men.[2] It involves the collection and storage of sperm, ideally before cancer treatment begins. The samples are kept frozen at a lab or sperm bank until they are needed. Sperm can be stored in this way for many years. After being thawed, the sperm can be used for intrauterine insemination (IUI) or in vitro fertilization (IVF). During IUI, sperm are placed directly into a woman’s uterus. During IVF, mature eggs are removed from a woman’s ovary and mixed with the sperm in the lab. Embryos that result from IVF can then be placed in a woman’s uterus or frozen for later use.

If a sample contains very few viable sperm (or if a man has already undergone cancer treatment and has a low sperm count), another approach may be used to fertilize an egg. Intracytoplasmic sperm injection (ICSI) requires only a small number of healthy sperm, along with mature eggs that have been collected from a woman’s ovary. A single sperm is injected directly into each egg. The embryos that develop can then be placed in a woman’s uterus or frozen for later use.

If it is not possible to collect sperm from ejaculate, it may in some cases be possible to collect sperm directly from the testicles. This approach is still investigational.

Finally, it may also be possible to modify some cancer treatments to minimize their effects on subsequent fertility. During radiation therapy, for example, it may be possible to shield the testes in order to preserve sperm production.

Pregnancy after cancer

In the event that your fertility is not affected by cancer treatment (or recovers quickly or unexpectedly), you and your partner should use birth control if you do not wish to have a child. If you are trying to conceive a child naturally, your doctor may advise you to wait for several months after treatment; this allows for the elimination of sperm that may have been damaged during treatment.

In general, the risk of birth defects in children born to cancer survivors appears to be similar to the risk in the general population.[3] If your cancer was due to a hereditary cancer syndrome, such as Lynch syndrome (hereditary nonpolyposis colorectal cancer), your children may inherit the gene mutation responsible for your family’s increased risk of cancer. Talking with a genetic counselor may be helpful.

Other options for parenthood

Not all men have the luxury of being able to explore their reproductive options before beginning cancer treatment, and not all men will find a fertility preservation option that meets their needs. But there are still ways to become a parent. Discussion of other routes to parenthood may be a painful topic for men who want to father a child but cannot. But as cancer survivors consider how best to build their families, methods such as adoption are important options.

Adoption: Couples and individuals who wish to adopt have a range of options, including different types of domestic and international adoptions. You may wish to start by learning about the adoption laws in your state and by talking with other adoptive parents about the professionals and agencies they worked with. Before selecting an adoption agency, you may wish to talk with them about their attitudes toward placing a child with a cancer survivor. Many agencies will be receptive toward this, but it’s important to know before making a final decision.

Donor Sperm: Donor sperm is readily available from sperm banks and can be used for either intrauterine insemination or in vitro fertilization.

Individual decisions within a larger community

The decisions that you make about building a family (or about coming to terms with not building a family) will be intensely personal, but know that you are part of a larger community of patients and healthcare providers who are grappling with these issues.  To think about future parenthood is to think about life after cancer. For many people with cancer, planning for the future may provide the motivation needed to get through treatment.

More information?

Discuss with others…. http://cancerconnect.com/groups/young-adults/topics/fertility-after-cancer-treatment

Fertile Hope (www.fertilehope.org) provides a range of fertility resources for people with cancer.

References:

How does cancer treatment affect fertility in women?

Chemotherapy: Many chemotherapy drugs are toxic to the egg cells (oocytes) in the ovaries. If the number of remaining oocytes in the ovaries reaches a critically low point during treatment, women experience “acute ovarian failure.” This means that the ovaries stop functioning during or shortly after cancer treatment. If oocytes are lost during treatment but do not reach this critically low point, women are at risk for early menopause but may still be able to get pregnant for some time after treatment.

Radiation: Radiation to the pelvis can also destroy oocytes. Radiation to the pelvis can also affect uterine growth and blood flow, particularly if received before puberty.[1] A poorly developed uterus may make a woman more likely to have a miscarriage, or more likely to have a preterm or low-birthweight infant.

Surgery: Some cancers require surgical removal of the uterus, the ovaries, or both.

The effects of cancer treatment on fertility can vary substantially by age. Younger women, who have a larger pool of oocytes when they start cancer treatment, are more likely than older women to be able to get pregnant after treatment.[2]

Options for preserving fertility in women

If possible, women should talk with their doctor about their future fertility before beginning cancer treatment. Some options for preserving fertility require that steps be taken before cancer treatment begins.

One of the most established approaches for preserving fertility among female cancer patients is embryo freezing.[3] Before starting cancer treatment, a woman would be given hormones to stimulate the development of eggs in her ovaries. Mature eggs would be removed and fertilized with the sperm of her husband, partner or a sperm donor. The embryos that result from these fertilized eggs would be frozen for later use.

Although embryo freezing is an established approach to helping women become pregnant after cancer, there are downsides. A woman may not currently have a male partner and may be unwilling to use an anonymous sperm donor. It’s also important to be aware that embryo freezing takes approximately two weeks after the start of a woman’s period. If a woman needs to begin cancer treatment immediately, she may not be able to go through this process. Finally, this approach is only an option for women of childbearing age; stimulating the ovaries to produce mature eggs is not an option for girls who develop cancer during childhood.

Several other options are still in the experimental phase. One approach being explored is the freezing of unfertilized eggs.3 Once again, the ovaries would be stimulated to produce mature eggs before cancer treatment begins. The eggs would then be frozen without being fertilized by sperm. Currently, freezing unfertilized eggs is less likely to result in pregnancy than freezing embryos, largely because unfertilized eggs are less likely than embryos to survive the process of freezing and thawing. Nevertheless, it may be an option for women who do not have a male partner at the time of their cancer diagnosis, and it avoids the difficult issue of what to do with unused embryos.

Another promising but still experimental approach is to freeze all or a part of an ovary before cancer treatment.[4] After treatment, the ovarian tissue is implanted either back in the woman’s pelvis or in another location (such as under her skin). If this process is successful, the ovarian tissue will begin producing eggs. A safety concern with this approach is the possibility of reintroducing cancer cells along with the ovarian tissue, and the tissue will need to be carefully screened for cancer before it is transplanted.4

Finally, it may also be possible to modify some cancer treatments to minimize their effects on subsequent fertility. For example, shielding the ovaries during radiation, or moving the ovaries out of the radiation field, may protect them from the effects of radiation. Scientists are also exploring whether using drugs to suppress the activity of the ovaries during chemotherapy will make the ovaries less susceptible to damage by chemotherapy.[5] For women with certain types of cervical or ovarian cancer, fertility-preserving surgery may also be an option.[6] It’s important to understand that only specific subsets of patients will be candidates for these approaches, and that some of the methods are still in the early stages of evaluation.

Pregnancy after cancer

In addition to having concerns about their ability to get pregnant, women may have concerns about whether pregnancy after cancer treatment will be safe for themselves and their children. While there is a limited amount of information about these topics, the news is generally good.

The risk of cancer recurrence during or after pregnancy has been most studied in women with breast cancer, and these studies generally have reported that pregnancy does not increase the risk of breast cancer recurrence. [7] Many doctors, however, suggest waiting for a period of time after treatment before becoming pregnant. [8]

If chemotherapy or radiation therapy has damaged her heart or lungs, a woman may also have concerns about the strain that pregnancy will put on her body. Studies of breast cancer survivors suggest that long-term heart problems are uncommon after chemotherapy or radiation therapy, [9] but a woman may wish to talk with her doctor about her current health status and the likely effects of pregnancy.

Children born after their mother’s cancer treatment do not appear to be more likely than other children to have birth defects or cancer.[10] If a woman’s cancer was due to a hereditary cancer syndrome, such as Lynch syndrome (hereditary nonpolyposis colorectal cancer), her child may inherit the gene mutation responsible for her family’s increased risk of cancer. Talking with a genetic counselor may help clarify the child’s risk.

When planning for pregnancy, be aware that some cancer treatments may cause you to have an early menopause even if your periods resume after treatment. Also be aware that you may be capable of conceiving even if your periods do not resume; continue to use birth control if you do not wish to become pregnant.

Other Options for Parenthood

Not all women have the luxury of being able to explore their reproductive options before beginning cancer treatment, and not all women will find a fertility preservation option that meets their needs. But there are still ways to become a parent. Discussion of other routes to parenthood may be a painful topic for women who want to become pregnant and cannot. But as cancer survivors consider how best to build their families, methods such as adoption are important options.

Adoption: Couples and individuals who wish to adopt have a range of options, including different types of domestic and international adoptions. You may wish to start by learning about the adoption laws in your state and by talking with other adoptive parents about the professionals and agencies they worked with. Before selecting an adoption agency, women may wish to talk with them about their attitudes toward placing a child with a cancer survivor. Many agencies will be receptive toward this, but it’s important to know before making a final decision.

Egg Donation: Women who still have a uterus may be able to become pregnant using an egg donated by another woman. Through in vitro fertilization, the donated egg would be fertilized by the cancer survivor’s male partner or a sperm donor, and implanted in her uterus. Alternatively, another couple may donate a frozen embryo that could be implanted in her uterus.

Gestational Carrier or Surrogate: Women who do not have a uterus, or who are otherwise unable to sustain a pregnancy, may be able to have another woman carry a pregnancy for them. If the cancer survivor has functioning ovaries, her own egg can be fertilized by her male partner’s sperm and transferred to the uterus of another woman. In this case, the woman who carries the pregnancy is known as a gestational carrier. If the cancer survivor does not have functioning ovaries, another woman can both donate an egg and carry the pregnancy. This is the arrangement traditionally known as surrogacy.

Individual Decisions Within a Larger Community

The decisions that you make about building a family (or about coming to terms with not building a family) will be intensely personal, but know that you are part of a larger community of patients and healthcare providers who are grappling with these issues.

To think about future parenthood is to think about life after cancer. For many people with cancer, planning for the future may provide the motivation needed to get through treatment.

More Information?

Discuss with others….. http://cancerconnect.com/groups/young-adults/topics/fertility-after-cancer-treatment

Fertile Hope (www.fertilehope.org) provides a range of fertility resources for people with cancer.

References:

A growing body of evidence suggests that aspirin may reduce the risk of several types of cancer, with particularly strong evidence for colorectal cancer. Not all studies have found a benefit, however, and any potential benefits of aspirin must be weighed against risks such as bleeding.

To further explore the relationships between daily aspirin and cancer, researchers conducted a combined analysis of 51 previous randomized trials.[1] The trials were originally designed to evaluate the effect of daily aspirin on outcomes such as heart disease, but information about cancer was also available.

• Daily aspirin reduced cancer deaths. After five years, aspirin users had a 37 percent reduction in risk of cancer death.
• Aspirin also reduced the likelihood of developing cancer. From three years onward, aspirin users had a 24 percent reduction in the risk of being diagnosed with cancer.
• As expected, aspirin carried a risk of major bleeding, but this risk appeared to diminish over time.

Another study published in the same issue of The Lancet evaluated the effect of daily aspirin on cancer metastasis (the spread of cancer from its original site to other parts of the body). The study focused on 987 people who were diagnosed with cancer while participating in one of five trials of aspirin use. Those who were taking aspirin were less likely to have metastatic cancer than those who were not taking aspirin.[2]

These results suggest that regular aspirin use may reduce cancer incidence and mortality, but concerns remain about the risks of regular aspirin use in healthy individuals. People who are considering using aspirin on a regular basis are advised to discuss the risks and benefits with their physician.

References:

Lung cancer remains the leading cause of cancer death among both men and women in theUnited States. Each year, roughly 88,000 men and 73,000 women die of the disease.

Although lung cancer can develop in non-smokers, roughly 90 percent of lung cancer deaths in men and 80 percent of lung cancer deaths in women are due to smoking. Smoking is also linked with several other types of cancer, including cancers of the throat, mouth, nasal cavity, esophagus, stomach, pancreas, kidney, bladder, and cervix, and acute myeloid leukemia.[1]

Since the 1950s, increased public awareness of the risks of smoking, coupled with tobacco control efforts such as higher cigarette taxes and restriction of smoking in public places, has reduced the rate of smoking in the US. To evaluate the effect that that this has had on lung cancer mortality, researchers developed statistical models that assessed number of lung cancer deaths prevented during the period 1975-2000.[2]

• The changes in smoking behavior that began in the 1950s prevented an estimated 795,851 lung cancer deaths during 1975-2000.
• In the year 2000 alone, more than 70,000 lung cancer deaths were prevented.

Although the prevention of almost 800,000 lung cancer deaths is good news, this number is a fraction of what could have been prevented if smoking rates had dropped even further. Currently, an estimated 21 percent of theUSpopulation continues to smoke. Encouraging smoking cessation, and preventing young people from picking up the habit in the first place, are still important parts of the fight against lung cancer.

References:

Lung cancer remains the leading cause of death in theUnited States. Each year, more than 87,000 men and 72,000 women die of the disease.

Diesel exhaust is composed of fine particles that can become lodged in the lung. The National Toxicology Program of the US Department of Health and Human Services has classified diesel exhaust as “reasonably anticipated to be a human carcinogen.”

To collect better information about the relationship between exposure to diesel exhaust and health outcomes, researchers from the National Cancer Institute (NCI) and the National Institute for Occupational Safety and Health (NIOSH) conducted the Diesel Exhaust in Miners Study.

The study involved more than 12,000 workers at eight non-metal mining facilities. Non-metal mining facilities were chosen because these types of mines often involve exposure to diesel exhaust from heavy equipment, but usually do not involve high levels of exposure to other causes of lung cancer such as radon, silica, or asbestos. The non-metal substances that were mined for were limestone, potash, salt, and trona.

Measurements of air taken at the mines allowed researchers to develop estimates of diesel exhaust exposure for each job and each year. Information was available for people who worked underground as well as people who worked on the surface.

Two reports were recently published from the study: the first assessed all causes of death among all subjects, and found a higher rate of lung cancer deaths among workers with the highest level of exposure to diesel exhaust.

The second report involved a closer analysis of the lung cancer deaths, and accounted for other lung cancer risk factors such as smoking, employment in other high-risk jobs, and history of respiratory diseases. Key findings from the second report include the following:

• Compared with the workers with the least exposure to diesel exhaust, those who had the highest exposure were roughly three times more likely to die of lung cancer.
• In the subset of workers who were non-smokers, those who had the highest exposure to diesel exhaust were seven times more likely to die of lung cancer.

The most heavily exposed miners had levels of exposure that were well above that of the generalUSpopulation. Lightly exposed underground miners, however, had a level of exposure that is similar to that experienced by people who spend a lifetime in a heavily polluted urban area. This level of exposure was linked with a 50 percent increased risk of lung cancer. The risk from very low levels of exposure to diesel exhaust is uncertain.

The results from these studies provide further evidence that diesel exhaust may increase the risk of lung cancer in humans. Newer diesel engines with lower emissions may reduce the health risks.

References:

National Cancer Institute Press Release. Heavy exposure to diesel exhaust linked to lung cancer death in miners. March 2, 2012.

National Cancer Institute Questions and Answers. Diesel Exhaust in Miners Study: Questions and Answers. March 2, 2012.

Silverman DT, Samaniac CM, Lubin JH, et al. The diesel exhaust in miners study: a nested case-control study of lung cancer and diesel exhaust. J Natl Cancer Inst. March 2, 2012. doi:10.1093/jnci/djs034.

Attfield MD, Schlieff PL, Lubin JH, et al. The diesel exhaust in miners study: a cohort mortality study with emphasis on lung cancer. J Natl Cancer Inst. March 2, 2012. doi:10.1093/jnci/djs035.

Lung cancer remains the leading cause of cancer death in theUnited States. Non–small cell lung cancer (NSCLC) accounts for approximately 85% of all lung cancers.

Treatment of NSCLC may involve surgery, chemotherapy, targeted therapy, radiation therapy, or some combination of these approaches.

The current study explored the treatment of older patients with Stage III NSCLC that had spread to certain lymph nodes (N2). After surgery to treat this stage of lung cancer, some patients may also receive radiation therapy in an effort to reduce the risk of cancer recurrence. There has been no clear evidence, however, that routine postoperative radiation therapy provides a benefit for these patients.

To examine the use of postoperative radiation therapy in older patients with Stage III, N2 NSCLC, researchers collected information from a largeUScancer registry and Medicare records. Information was available about 1,307 patients.

• More than half (54 percent) received postoperative radiation therapy.
• People who received radiation therapy did not have better survival than people who did not receive radiation therapy.

Because this was not a randomized clinical trial, the results are not definitive. Nevertheless, the results suggest that that many older lung cancer patients are receiving a treatment (postoperative radiation therapy) that may not provide a benefit and that comes with side effects and costs. Results from ongoing clinical trials may shed more light on this issue.

Whether similar results would be seen in younger patients or in patients with a different pattern of lymph node involvement is unknown.

Reference: Wisnivesky JP, Halm EA, Bonomi M, Smith C, Mhango G, Bagiella E. Postoperative radiotherapy for elderly patients with stage III lung cancer. Cancer. Early online publication February 13, 2012.

Lung cancer is the leading cause of cancer death among both men and women in the United States. The disease is often detected at an advanced, difficult-to-treat stage.

Cancer screening involves the use of tests to detect cancer at an early stage in people who don’t have any symptoms of the disease. For cancers such as breast cancer, colorectal cancer, and cervical cancer, screening has contributed to decreased rates of cancer death. Understandably, there has also been a great deal of interest in whether lung cancer screening with tests such as CT scans could reduce lung cancer mortality.

Promising results for screening with helical low-dose CT were published earlier this year in the New England Journal of Medicine.[1] The National Lung Screening Trial (NLST) enrolled current and former heavy smokers. Study participants were screened with either chest x-rays or low-dose spiral CT. People in the CT group were 20% less likely to die of lung cancer.

Based on review of the NLST and other studies, the NCCN guidelines for lung cancer screening recommend screening with helical low-dose CT for selected individuals at high risk of lung cancer.[2] Specifically, the NCCN panel recommended annual screening for people between the ages of 55 and 74 who have a history of at least 30 pack-years of smoking (a pack-year is equivalent to smoking a pack per day for a year), and who, if they are no longer smoking, quit within the last 15 years. Some other high-risk people may also be candidates for screening, but with less evidence to support screening.

The NCCN does not recommend routine lung cancer screening for people at low or moderate risk of lung cancer.

Other organizations—such as the American Cancer Society—have still not completed their review of the most recent lung cancer screening data. People who have questions about the potential risks and benefits of screening are advised to discuss the issue with their physician.

References:

[2] NCCN press release. NCCN announces new addition to library of guidelines: NCCN guidelines for lung cancer screening. November 9, 2011.