Patients who have been diagnosed with lung cancer do not all quit smoking, with a third found to still smoke a year after they have been diagnosed. These are the findings of a recent study on smoking rates in cancer patients at Massachusetts General Hospital.

The study, which was conducted in partnership with Harvard Medical School in Boston, questioned over 5000 patients who had been diagnosed with lung cancer or colorectal cancer. The results showed that 39% of lung cancer patients and 14% of colon cancer patients were still smoking on diagnosis. Patients were also questioned five months after they had been diagnosed, with 14 percent of lung cancer patients and 9 percent of colorectal cancer patients still smoking respectively.

Researchers reported that the majority of those patients who had been diagnosed with lung and colon cancer had tried to quit, but some returned to smoking within a relatively short period. Other patients were reported not to have tried to quit at all, however.

The findings of the study, which were published in the latest edition of CANCER, a journal of the American Cancer Society, are a cause for concern, especially for doctors who claim that smoking can reduce the effectiveness of cancer treatments. Some specialists claim that patients who continue to smoke may reduce the effect of chemotherapy and radiotherapy treatments. In addition, continuing to smoke can also lead to an increased risk of developing further smoking-related disease, ultimately reducing survival rates.