When testicular cancer runs in the family, men should be checking themselves regularly for tell-tale signs — but fewer than half of such men perform regular self-exams, new research shows.

The biggest factor by far influencing whether these men did the exams was whether or not their physicians recommended they do so.

"This provides yet another example of how potent an influence the physician can be with regard to cancer prevention behavior in patients, and underscores the importance of physicians including such recommendations in the course of ongoing health care discussions," Dr. Susan Vadaparampil of the Moffitt Cancer Center in Tampa, Florida and her colleagues say.

Men who have a family history of testicular cancer are four to nine times more likely to develop the disease themselves compared to the general population, according to Vadaparampil and her team. While this disease represents just 1 percent of all cancers in men, it is the most common cancer among men 20 to 35 years old.

There have been several studies of testicular self-exam practices among men in the general population, but not men at high risk for testicular cancer, the researchers add. To investigate, they surveyed 99 men participating in a National Cancer Institute study of hereditary testicular cancer. All had at least two first- or second-degree relatives with testicular cancer.

The researchers defined doing testicular self-exams regularly as having performed the exam six or more times in the previous year. Forty-six percent of the men reported regularly doing the exams, while 51 percent said they didn't, the team reports in the online medical journal Hereditary Cancer in Clinical Practice. The remaining 3 percent did not answer the question.

Men whose physicians had recommended testicular self-exams were 6.6 times more likely to perform them regularly than men who had not had that advice, while those who reported high levels of worry about the disease were 1.6 times more likely to do so than those who were less fearful.

The question of whether men in general should perform self-exams to watch for testicular cancer remains a matter of debate, the researchers say, with some experts arguing that it would not be beneficial given the success of chemotherapy in treating even late-stage disease. The American Cancer Society does recommend that men with a family history of testicular cancer "seriously consider" examining themselves regularly.

Nevertheless, the researchers add, early detection by self-examination has the potential to reduce harm related to treatment, because early stage testicular cancer can often be treated with surgery followed by close monitoring, with no need for chemo.

Vadaparampil and her team conclude by noting that they do recommend their patients with a family history of testicular cancer perform self-exams monthly. "Given that testicular cancer is a disease which affects young men during the most productive period of their lives, there is potential for real economic and psychosocial benefit in attempting to minimize treatment-associated costs and morbidity," they conclude.