May 9, 2012 (Phoenix, Arizona) — Breast cancer in men represents only about 1% of all breast cancers; however, the tumors tend to be larger, the cancer more advanced, and overall survival is substantially lower than for women, according to research presented here at the American Society of Breast Surgeons 13th Annual Meeting.
For their study, investigators used data from the National Cancer Data Base on all patients with breast cancer from 1998 to 2007. They first compared the cases for differences in sex, then for age, race/ethnicity, histology, grade, tumor size, lymph node involvement, hormone-receptor status, course of first treatment, and overall survival.
"This study differs from others mainly in its magnitude," lead author Jon Greif, DO, a breast surgeon from Oakland, California, told Medscape Medical News. "It is, by far, the largest series of male breast cancer ever studied."
The study involved 13,457 cases of male breast cancer, representing 0.9% of all breast cancers, and 1,439,866 cases of female breast cancer.
The incidence of male breast cancer, compared with female breast cancer, was higher among blacks (11.7% vs 9.9%; odds ratio [OR], 1.19), lower among Hispanics (3.6% vs 4.5%; OR, 0.74), and higher among older patients (63 vs 59 years).
Overall, male cancers were more advanced than female cancers, and male tumors were larger (median, 20.0 vs 15.0 mm). Males were less likely to have grade 1 tumors (16.0% vs 20.7%), more likely to have lymph node metastasis (41.9% vs 33.2%; OR, 1.45), and more likely to have distant metastasis (4 vs 3; OR, 1.39).
In addition, males had lower rates of lobular carcinoma (10% vs 18%; OR, 0.51) and a greater likelihood of being estrogen-receptor (ER) positive (88.3% vs 78.2%; OR, 2.10) and progesterone-receptor positive (76.8% vs 67.0%; OR, 1.63).
Males were less likely than females to have a partial mastectomy (33% vs 62%; OR, 0.31) and to receive radiation (35.9% vs 50.4%; OR, 0.55).
Chemotherapy rates were not significantly different between males and females, and there were only small differences in hormonal therapy rates.
Overall survival rates, however, were significantly different. Females with breast cancer had significantly better 5-year overall survival for stage 0 (94% vs 90%), stage I (90% vs 87%), and stage II (82% vs 74%) breast cancer (P < .0001 for all).
However, there were no significant differences between females and males in overall survival for stage III (56.9% vs 56.5%; P = .99) or stage IV (19% vs 16%; P = .20) disease.
The findings provide evidence that, for all of the expansive breast cancer awareness efforts, the message still falls largely on deaf ears when it comes to men.
"Absolutely there is less awareness among men and their healthcare providers," Dr. Greif said.
"Many are unaware that men even get breast cancer," he said. "A program of increasing awareness, and developing screening for men at high risk — genetically, by family history, by exposure to radiation or other known carcinogens, and by having had the disease before — would all be helpful."
"The basics of prevention are a healthy lifestyle — eat healthy, exercise, maintain a healthy weight, don't smoke, limit alcohol, etc."
He noted that the study has several limitations, including a lack of data on cause of death and certain screening specifics.
"The major limitation of our study is that the database does not let us see exactly what the men in the study are dying of; certainly some are dying of diseases other than breast cancer," he said.
"Another limitation is that we don't exclude from analysis the women whose cancers were detected by screening — so-called lead-time bias. This is a major reason that they have earlier tumors and do better. It's a limitation, but it also underscores our point — we need to raise awareness about male breast cancer."
According to breast surgeon Deanna Attai, MD, head of the Center for Breast Care in Burbank, California, several factors could explain the trends.
"Men in the study presented with more advanced-stage disease, possibly because they were less likely to have grade 1 tumors, and possibly because there are no generally accepted screening guidelines for men," she said.
Survival differences were seen "even when men were compared stage-for-stage with women. That might be due to several factors, or a combination of factors — higher-grade tumors and tumors that are less likely to be treated with tamoxifen even though most of the tumors are ER-positive. We don't know from the database why tamoxifen was less likely to be used. Maybe it was offered and the side effects made it intolerable, or maybe it was not offered," Dr. Attai explained.
"Perhaps there is even the issue that men generally don't live as long as women."
Despite several unanswered questions, the research is significant, Dr. Attai said.
"It's the largest review of male breast cancer, and it raises awareness — in men and their physicians — that, at the very least, periodic self-exams and clinical exam by the physician are important."
Dr. Greif and Dr. Attai have disclosed no relevant financial relationships.
American Society of Breast Surgeons (ASBS) 13th Annual Meeting. Abstract 0104. Presented May 4, 2012.
Medscape Medical News © 2012 WebMD, LLC
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Cite this: Male Breast Cancers Less Common, More Advanced at Diagnosis - Medscape - May 09, 2012.