Mixed Small Cell/Non-Small Cell Lung Cancer
My father was recently diagnosed with lung cancer, both small cell (limited stage) and non-small cell (Stage IIIA, T2N2M0). Apparently, it is rare to have both types of lung cancer at the same time. He is currently getting chemotherapy once per month for 3 days straight concurrently with daily radiation therapy for 7 weeks. My questions are as follows: how rare is it to have both types of lung cancer? What is the prognosis for someone like my father? Are there any clinical trials for someone with both types? I can find a lot of information about the individual types of lung cancer but not about having both.
Li Liu, MD, Editorial Assistant for OncoLink, responds:
Lung cancer is the leading cause of cancer death for both men and women. In the year 2013, there will be an estimated 228,190 new cases of lung cancer in the United States. About 159,480 people will die of lung cancer in the United States. Small cell lung cancer accounts for about 15% of all lung cancers. Small cell carcinoma (formerly known as oat cell carcinoma) comprises more than 90% of all small cell lung cancer cases. The remaining 10% are mixed small cell/non-small cell carcinomas (Cancer 1988 Sep 1; 62(5): 973-7) such as your father's.
Treatment generally involves multimodality (surgery, chemotherapy, radiation) therapy, but the cure rate is unfortunately low. Two earlier single-institution studies reported diminished response to combination chemotherapy and inferior survival for patients with mixed carcinomas compared with patients having small cell carcinoma without a non-small cell component (Cancer 1983 Dec 1; 52(11): 2144-50; Cancer 1982 Dec 15; 50(12): 2894-902). However, a more recent report from Vanderbilt University showed that 2% of small cell carcinoma patients had the combined subtype, with non-small cell elements admixed with small cell histologically. These patients tended to have more localized, sometimes surgically resectable disease and a more favorable prognosis (Journal of Clinical Oncology 1989 May;7(5):607-12). Current think is that patients who have mixed histologies, like your father, should be treated as those the entire tumor is a small cell lung cancer. However, all patients should be managed individually based upon their stage of disease, age, and general medical condition.