lung cancer, thanks to the ubiquitous habit of smoking, is the No. 1 cancer in the world, and the leading cause of cancer deaths. Worldwide in 2002, there were 1.35 million new cases of lung cancer and 1.18 million lung cancer related deaths. Non-small cell lung cancer (NSCLC) is the most common kind, accounting for 80 to 85 percent of cases.
Until now, complete removal of early lung cancers at surgery provided the best chance for long-term survival. Sometimes this was followed by radiation therapy. Cancer doctors rarely talk cure; rather, they couch the success of therapy in terms of “five-year survival rates.”
How many patients are alive five years after the initial diagnosis? Five-year survivals for patients with operable NSCLC vary from 23 to 67 percent, depending on the size of the tumor, how far the cancer has invaded and whether the cancer has spread to the lymph nodes.
Recurrences that lead to death result mainly from cancer that shows up outside the chest cavity. That implies that cancer cells already may have spread far away from the original cancer at the time of the original diagnosis. We call these “micrometastases,” and doctors have been looking for the right chemotherapy that could knock off these cells and lead to better survival rates.
This type of adjuvant (added) therapy has a well-established role in the treatment of breast and colon cancer, but results from various studies of adjuvant chemotherapy in NSCLC so far have not been promising.
In a study that could have widespread implications for the treatment of early lung cancers that are completely removed at the time of surgery, researchers reported in the New England Journal of Medicine that an adjuvant chemotherapy regimen significantly improved survival rates and death rates in these patients.
Researchers randomly assigned 482 patients with stage IB or stage II NSCLC to either the chemotherapy group or to the observation group. The chemotherapy group was scheduled to get four cycles of treatment. This could not be a double-blind study because, frankly, chemotherapy has some pretty gnarly side effects and a person would know whether they were getting the real thing, and so would their doctors.
The researchers looked at overall survival and recurrence-free survival. The study used cisplatin, a chemotherapy drug that’s been around for a while, and a newer drug called vinorelbine. Vinorelbine, a “third-generation” chemotherapeutic drug, works well in patients with advanced metastatic lung cancer, and so they decided to try it in these patients. This trial is the first to treat all patients in the treatment arm with a third-generation drug.
Follow-up of patients in the study ranged from one and a half to nine years. Of the chemotherapy group, 36 percent had a recurrence of their disease, versus 49.6 percent in the observation group. The average (median) survival in the observation group was 46.7 months, and the median hasn’t been reached yet in the chemotherapy group, meaning some in that group are alive and without detectable disease.
The five-year recurrence free-survival rate was 61 percent in the treated group and 49 percent in the observation group. The overall survival advantage at five years was 15 percentage points. In other words, for every 100 patients with NSCLC treated with chemotherapy, 15 more were alive after five years compared to the group that got only surgery. Given the number of people diagnosed with lung cancer every year, this change in treatment strategy can have an enormous effect on long-term survival in patients whose cancer is detected in the early stages.
When the researchers did a subgroup analysis, they found those with stage IB cancers did not seem to benefit like the stage II group, but the numbers were small. As they often say, “further research is needed.” Still, this is exciting news.
Of course, the chances of avoiding any treatment at all for lung cancer increase astronomically when you give up the cigarettes. An ounce of prevention….
Source: Spokesman Review
Revision date: June 14, 2011
Last revised: by Jorge P. Ribeiro, MD