Category Archives: Cancer News

Chemotherapy Benefits Gall Bladder Cancer

India along with countries of the Far East, Eastern Europe and Latin America have the highest incidence of gall bladder cancer in the world. Women from Delhi have an incidence of gall bladder cancer of 21.5 pere 100,000 persons, the highest in the world. Only 10-20% of the patients in developed countries have disease localized to the gall bladder at diagnosis. The number in developing countries is expected to be much smaller. Even when the disease is localized, 60% relapse within 5 years of diagnosis. About 80-90% of the patients will need chemotherapy for gall bladder cancer at presentation or at relapse. Chemotherapy is toxic and should only be used in advanced disease if it can achieve cure, prolong survival or relieve symptoms. There are large number patients of gall bladder cancer who need chemotherapy. Do they benefit from chemotherapy?

A study from India (J Clin Oncol 28:4581-4586;2010) compared chemotherapy with best supportive care (a euphemism for no active treatment used in oncology community) and showed that about 30% of the patients respond to chemotherapy. Also, chemotherapy increases the survival twofold. The focus of treatment of gall bladder cancer has been relief of biliary obstruction and symptoms. Chemotherapy will now form an important part of therapy for gall bladder cancer.

Oral Therapy Better Than Chemotherapy for Some Lung Cancers

Lung cancer is the commonest malignancy in the world accounting for about 1.2 million patients world over. Most of the patients present at an advanced stage. Chemotherapy prolongs life and gives symptomatic control in patients of advanced non-small cell lung cancer. The backbone of chemotherapy are the two platinum containing drugs, cisplatin and carboplatin. These are given as a two drug combination, the other drug being one of gemcitabine, pemetrexed, docetaxel, paclitaxel or vinorelbine. Half the treated patients will survive for 8-10 months, less than 10% of the patients survive 5 years.

Growth factors act via receptors to promote cell growth. Binding of the factor to the receptor switches on the receptors and induces cell division. When the growth factor dissociates from the receptor, the receptor is switched off and cell growth stops. Cancer is a disease resulting from mutations in growth promoting genes. Mutations that switch on the growth factor receptor gene permanently are common in cancer. Such a receptor behaves like a faulty electric switch that can not be turned off. It continues to promote cell growth even if there is no growth factor present. Activating mutations of the epithelial growth factor receptor (EGFR) gene are seen in non-small cell lung cancer.

One of the landmarks in oncology has been the development of drugs that can switch off activated growth promoting genes. If conventional chemotherapy is like carpet bombing, the use of these drugs is like a sniper attack. Two drugs erlotinib and gefitinib, that can be administered orally, are able to switch off EGFR switched on by what are known as tyrosine kinase domain mutations. This results in the arrest of growth of lung carcinoma cells. Oncologists have learned the hard way that every drug that shrinks a tumour does not prolong life. What impact does therapy with gefitinib or erlotinib have on patients with advanced non-small cell lung cancer?

Results from the the North-East Japan Study Group suggests that gefitinib is better than chemotherapy for patients with non-small cell lung cancer who have tyrosine kinase domain mutations in EGFR. Progression was 70% less likely if such patients were treated with gefitinib compared to chemotherapy. Gefitinib is less likely to cause adverse effects than chemotherapy. Patients usually have rash. Patients who develop rash with anti-EGFR agents appear to have a better tumour response. The only serious side effect of the drug is interstitial pneumonitis which is very rare. Gefitinib along with erlotinib is an option for patients who harbour mutations in the tyrosine kinase domain of EGFR. For some reason a bulk of patients who have gefitinib sensitizing mutations are non-smoker Asian women with adenocarcinoma of the lung.

Osteoporosis Therapy Reduces the Risk of Breast Cancer

The drug therapy of postmenopausal osteoporosis includes hormone replacement therapy, selective oestrogen receptor modifiers (SERMS) and bisphosphonates. Unlike hormone replacement therapy and SERMS bisphosphonates do not carry the risk of breast cancer. In fact, in vitro studies have shown that bisphosphonates may have an anti-cancer effect and this effect may not be limited to bone metastasis. There are two classes of bisphosphonates nitrogen containing (alendronate, risedronate, zoledronate and ibandronate) and those without nitrogen (clodronate, etidronate). Nitrogen containing bisphosphonates have anti-cancer properties. Are women receiving bisphosphonates for osteoporosis protected from cancer?

Two recently published studies suggest that bisphosphonates taken for osteoporosis reduce the risk of cancer. The Women’s Health Initiative Observational Study, that included 154,768 women receiving bisphosphonates for osteoporosis suggest that bisphosphonates reduce the risk of breast cancer by 32%. The Breast Cancer in Northern Israel Study showed a 28% risk reduction in breast cancer in receiving bisphosphonates for osteoporosis. An earlier study has shown a 33% reduction in breast cancer with the use of bisphosphonates.

Breast cancer is one of the most common cancers in women. Breast cancer accounts for about one million cancers per year. Bisphosphonates could prevent 300,000 of these. Should bisphosphonates be used for chemoprophylaxis of breast cancer?

Bisphosphonates are associated with rare serious adverse effects including gastric and oesophageal ulcers, jaw necrosis and possible atrial fibrillation and increased risk of oesophageal carcinoma. Use of bisphosphonates for chemoprophylaxis of breast cancer would expose normal individuals to this risk. Unless the benefits of bisphosphonates in breast cancer prevention are documented in a controlled trial, bisphosphonates can not be recommended for use in prophylaxis of breast cancer. However the reduction in the risk of breast cancer may be a reason of choosing bisphosphonates over other drug therapy for osteoporosis.