According to a new study women who have completed five years of systematic therapy for breast cancer could still run the risk of a relapse though the rate is low.
The study, published online in the Journal of the National Cancer Institute, studied 2838 cancer patients whose disease varied from stage I to III had been treated with some form of therapy and had remained disease-free for the landmark five years.
All of them had a various treatments ranging from surgery, chemotherapy, radiotherapy to endocrine therapy. The findings showed that 89% of the patients remained disease free 10 years after diagnosis and 81% after 15 years.
The study's lead author, Dr. Abenaa Brewster, a medical oncologist at the University of Texas M.D. Anderson Cancer Center in Houston, said "Patients often ask me, 'Now that I've survived my breast cancer, what is my future risk of a recurrence?' This is an answer we've had a hard time giving. They remain really terrified about their risk."
The risk or recurrence depended on the stage of the cancer and tumor type and women with stage I disease had a 7 % chance of relapse; stage II, 11% ; while stage III, 13%.
"I would like to think these numbers are smaller than women think they are." Dr. Brewster said many of the women “remain terrified they are going to relapse. I think the message for women is, the risk may not be as large as they think."
The study also found that two types of tumors are less likely to recur in the first five years, slow growing and estrogen fueled tumors and these recurred 10 -15 years after diagnosis. Medical experts are still trying to figure out how hormone receptor status affected the risk of relapse.
“Women who had ER-positive cancer were more likely to have late recurrences than those with ER-negative," Brewster said. This applied in the case for premenopausal and postmenopausal women. "Estrogen receptor status is a tumor marker we look at," Brewster said. "We know that those who have ER-positive tumors [have] cancers that are responsive to the effects of estrogen."
The American Cancer Society says about 183,000 women are diagnosed with breast cancer each year, and about 40,000 die of it with an overall, 89% of breast cancer patients surviving at least five years.
Dr. Len Lichtenfeld, deputy chief medical officer for the American Cancer Society, said "The major message is that even though women may have gone through five years of hormonal therapy, they are still at risk of relapse," he said. "Basically the jury is out on the potential value of additional treatment strategies once the five years is completed," Lichtenfeld said. "Based on this study, we need to be open to question whether other treatment programs may be appropriate in some of these women after the five-year period is completed."