Some scientists believe that surgery to remove a breast tumor may actually help the cancer spread and have recently reported that this same belief may be the exact reason black women are more likely to die of breast cancer.

There is apparently a widespread belief in parts of Africa and the United States that removing a tumor hastens death.

"I must say that I am sure there is more to this than just a myth," said Michael Retsky of Children's Hospital and Harvard Medical School in Boston, who shares his opinions in the International Journal of Surgery.

Retsky still urges any woman with breast cancer to have her tumor removed. And he says chemotherapy is such standard practice for any cancer threatening to spread. It's a safety net of sorts to catch the cells that get away. So if surgery causes cancer to spread, then in theory, chemotherapy should stop the spread.

Retsky, who is not suggesting any change in clinical practice, thinks the subject needs far more research. American Cancer Society experts, who tend to question this theory, agree.

"Whether or not the theory is correct, I have difficulty with the logic that they employed to get there," said oncologist Dr. Len Lichtenfeld of the American Cancer Society who says women should never delay treatment for breast cancer.

Retsky believes that perhaps surgery, by wounding the body, causes it to produce growth factors that fuel the growth of other, tiny tumors. Or maybe a primary tumor secretes some sort of factor that holds the other tumors in check. When the main tumor is removed, the smaller tumors grow.

But it could be that surgery does not cause a spread at all – and that any belief of this nature has no connection with breast cancer tendencies in black women. It may be that black women just have a genetic predisposition for more aggressive forms of the disease.

I think obesity will always carry with it a risk for health problems. And according to a new study released on Monday, men with prostate cancer who are overweight have a higher risk of tumor recurrence after radiation treatment than thinner men do. Specifically, moderately and severely overweight men had a 70 percent higher risk of recurrence than men who were not overweight -- as indicated by rising levels of PSA, a blood protein that can signal prostate cancer. It is not clear how exactly obesity affects the success of radiation treatment -- perhaps it's the fat tissue that secretes certain hormones that helps the cancer progress at a later time. Regardless, the study suggests that men who are overweight do not fare as well as those who are at an average weight -- and this gives men a definite reason to trim down.

Obesity in this study was characterized by body mass index -- BMI -- a statistic that takes into account height and weight. A man five feet, 10 inches tall would be considered normal weight at or below 184 pounds. He would be overweight at 185 to 209 pounds, mildly obese at 210 to 244 pounds, and moderately to severely obese at above 244 pounds. Moderately to severely obese men had almost twice the risk of developing elevated PSA levels, according to an epidemiologist who led research in the study -- which will be published in the August 1 issue of the scientific journal Cancer.