Herceptin® Evaluated in Advanced Bladder Cancer
by Dr. C.H. Weaver M.D. (06/2018)
According to the results of a Phase II clinical trial, Herceptin® (trastuzumab)-a targeted therapy used in the treatment of HER2-positive breast cancer-may have a role in the treatment of HER2-positive advanced bladder cancer. Larger studies will be necessary to further evaluate Herceptin in bladder cancer.
The bladder is a hollow organ located in the pelvis. Its primary function is to store urine (the waste produced when the kidneys filter the blood). Urine enters the bladder through two tubes called ureters, and leaves the bladder through a single tube called the urethra. The bladder has a muscular wall that allows it to get larger and smaller as urine is stored or emptied.
HER2 is a protein that has been most widely studied in the context of breast cancer. Twenty to thirty percent of breast cancers overexpress (make too much of) HER2.4 Overexpression of this protein leads to increased growth of cancer cells and a worse breast cancer prognosis.
Because some bladder cancers have also been found to overexpress HER2, researchers conducted a Phase II clinical trial to evaluate Herceptin in combination with chemotherapy among patients with HER2-positive advanced cancer of the bladder, renal pelvis, or ureter.6
Of 109 patients tested for HER2, 57 (52%) were positive. Forty-four of these patients were enrolled in the study. In addition to Herceptin, study participants received chemotherapy with paclitaxel, carboplatin, and gemcitabine.
- 11% of patients experienced a complete disappearance of detectable cancer, and 59% of patients experienced a partial disappearance of detectable cancer (overall response rate of 70%).
- Half the patients survived longer than 14 months.
- Heart problems are a potential side effect of Herceptin therapy, and 23% of study participants experienced heart complications. Few of these complications were severe.
The researchers conclude that additional study of the role of Herceptin in HER2-positive bladder cancer is warranted.
2 Ries LAG, Harkins D, Krapcho M, Mariotto A, Miller BA, Feuer EJ, Clegg L, Eisner MP, Horner MJ, Howlader N, Hayat M, Hankey BF, Edwards BK (eds). SEER Cancer Statistics Review, 1975-2003, National Cancer Institute. Bethesda, MD, http://seer.cancer.gov/csr/1975_2003/, based on November 2005 SEER data submission, posted to the SEER web site, 2006.
6 Hussain MHA, MacVicar GR, Petrylak DP et al. Trastuzumab, paclitaxel, carboplatin, and gemcitabine in advanced human epidermal growth factor receptor-2/neu-positive urothelial carcinoma: results of a multicenter phase II National Cancer Institute Trial. Journal of Clinical Oncology. 2007;25:2218-2224.