1. Progress in Breast Cancer
Breast cancer is the most common female cancer in America, and occurs in over 182,000 women annually. The probability is that one in six women will develop a breast tumor over the course of their lifetimes.
Fortunately, a great many women who are diagnosed with breast cancer will have a normal life expectancy. Effective prevention, early detection, and improved treatment are combining to result in near-normal life spans and relative freedom from malignant disease.
Screening mammography and greater use of adjuvant anticancer therapies are contributing to improved breast cancer survival and decreasing mortality rates. Preventive measures to help decrease the risk of breast cancer include limiting alcohol use, exercising regularly, maintaining a healthy weight, and breast-feeding for at least several months.
In addition to established anti-tumor therapy, several new treatments
have recently been developed:
1. Halaven (eribulin) – approved by the FDA in November 2010, this sea-sponge-derivative is indicated for treatment of metastatic breast cancer in patients who have previously received a anthracycline and taxane
2. Faslodex (fulvestrant) – a selective estrogen receptor down-regulator (SERD), and is approved by the FDA following antiestrogen therapy for hormone receptor-positive metastatic breast cancer in postmenopausal women with disease progression. Although initially, the approved dose of fulvestrant was 250 mg administered once monthly, the FDA has recently approved a higher dose of fulvestrant 500 mg monthly based on positive results from two studies.
Progress in Gastric Cancer
1. Herceptin (trastuzumab)- in metastatic gastric cancer, the biologic agent trastuzumab has been found to increase survival in patients with tumors that “overexpress” the HER2 oncogene. Trastuzumab was found to significantly improve overall survival in one study.
Progress in Pancreatic Cancer
Small-Molecule Targeted Therapies are non-biologic (synthetic)agents that have shown promise in certain pancreatic tumors. These agents target a number of cellular growth factor receptors, many of which function as tyrosine kinases, and the mammalian target of rapamycin (mTOR). Randomized trials have shown benefit from two such molecularly targeted agents: sunitinib and everolimus.
1. Sutent (sunitinib) – an orally active tyrosine kinase inhibitor for certain advanced pancreatic tumors. Sutent was administered in a placebo-controlled randomized trial of 171 patients and was associated with a significant six-month prolongation in median progression-free survival.
2. Afinitor (everolimus) – an mTOR inhibitor that was associated with a significant six-month prolongation in median progression-free survival in a placebo-controlled trial of 410 patients with a certain type of advanced, progressive pancreatic cancer.
Progress in Colorectal Cancer
Mutations of the KRAS proto-oncogene is an essential step in the development of many cancers. KRAS acts as a molecular on/off switch, and can activate or inhibit growth factors involved with malignant cell growth and proliferation. A single amino acid nucleotide substitution can activate a KRAS proto-oncogene mutation which are associated with resistance to the anticancer drugs Vectibix (panitumumab) and Erbitux (cetuximab). These agents target the epidermal growth factor receptor (EGFR).
1. Erbitux (cetuximab)- a large retrospective study has shown that patients with a “p.G13D mutation” who receive cetuximab for metastatic colorectal cancer, survived longer than did those with other K-ras mutations. Patients with a “p.G13D mutation” responded to Erbitux moderately well, and had an overall survival comparable to that of patients with wild-type K-ras.
In Part II of this review, additional topics in cancer progress will be addressed, including developments in treating malignancies of the lung and prostate.