Big Tumors Vulnerable to Chemo

Tumor size correlates to stronger chemotherapy effect

/ Author:  / Reviewed by: Robert Carlson, M.D

(RxWiki News) Chemotherapy is generally recommended for cancers where surgery is impossible, either due to metastasis, difficult location, or small size.  

Chemotherapy is also used to make sure no cancer remains after surgery, and sometimes before surgery to shrink the a tumor.

But a recent study showed that even though it's not usually used in advanced cancers, chemotherapy has an even greater effect on larger tumors than previously believed.

Ask your oncologist about recent studies on the benefits of chemotherapy in your cancer.

Research authored by Sinead Cuffe, MD, from the Department of Medical Oncology at Princess Margaret Hospital in Toronto, analyzed the relationship between tumor size and chemotherapy response, concluding that smaller cancers responded less well to chemotherapy.

The study also looked for any evidence of genetic influences on either size or chemotherapy response, and found that a mutation in the KRAS gene was on average, associated with shorter survival times.

While the idea that a larger tumor would receive a larger dose of a cancer drug is straightforward, evidence has been hard to come by.

Although it might be hard to believe there are any upsides to having a larger tumor, the study showed that at least for non small cell lung cancers, larger tumor size meant better odds of long term survival for these non small cell lung cancer patients.

The study used several previous clinical trials for data, finding that out of 461 lung cancer patients given chemotherapy for non small cell lung cancers, larger tumors were more susceptible to chemotherapy with platinum-based chemotherapy drugs.

The newest tumor classification system was used to describe the stage of the cancers, however, which may account for the difference in comparison to the conclusions of the original studies.

"Our study reinforces the pressing need for improved understanding of the impact of the new T-size descriptors on adjuvant chemotherapy effect," the authors say.

"This is particularly valid when we consider that up to 77 percent of surveyed lung cancer physicians would alter patient management in response to a change in stage designation."

The study will be published in the June edition of the Journal of Thoracic Oncology.

The study was sponsored by the International Association for the Study of Lung Cancer.

Reviewed by: 
Review Date: 
May 31, 2012
Last Updated:
June 4, 2012