I’ve lost count of how many doctors and researchers in the last two days have expressed alarm at the fact that mastectomies are on the rise. Several studies suggest that less surgery is better for women, that lumpectomy is better than mastectomy. Whether or not women who have lumpectomy plus radiation live longer than women who have a mastectomy, it is clear that a smaller surgery is not worse for women. And lumpectomy comes with fewer complications and lower cost.
In the opening Plenary Lecture yesterday, Dr. Jay Harris noted the rise in mastectomies at the same time there has been a reduction in local recurrence rates. His talk was on radiation, and his point is that the main benefit in reducing recurrence has come from the addition of adjuvant systemic therapy, not surgery or radiation. In 1970s, the 5-year local recurrence rate was about 10%; currently, worldwide the 5-year rate is about 2%. Dr. Harris notes that it is ironic that as breast-conserving therapy gets better, more patients choosing mastectomy.
Thursday morning’s General Session ended with three papers which compared lumpectomy (typically referred to in a research setting as “breast-conserving surgery”) and mastectomy.
A paper out of the Netherlands presented by Dr. van Maaren looked at 10 year distant metastasis free survival, comparing lumpectomy plus radiation versus mastectomy, for the first time. In the 1980s, several randomized controlled studies showed equal survival for lumpectomy with radiation and mastectomy. More recent observational studies have shown better survival for breast-conserving therapy. This study used the Netherlands Cancer Registry, which includes all patients diagnosed with cancer from 1989 forward, to compare 10 year overall survival rates for 37,207 patients after either breast-conserving therapy or mastectomy. Regardless of stage at diagnosis, women with lumpectomy and radiation did better, with 20% increased overall survival compared to mastectomy.
While the question and answer session (which included questions about selection bias) revealed that the true benefit is likely not as big as this, Dr. van Maaren does believe there is a real survival benefit that comes with lumpectomy and radiation, and hypothesized that the radiation therapy contributes to the better outcomes.
The second study (S3-06) was another retrospective study, this time of nine National Cancer Institute designated comprehensive cancer centers, looked at multiple surgical options. The study looked specifically at patients treated with systemic therapy before surgery (neoadjuvant treatment), as one of the aims of neoadjuvant therapies has been to improve candidacy for breast-conserving surgeries. And yet breast-conserving surgery rates are not increasing. In this study, one third of women received lumpectomy.
As with the prior Dutch study, women who had lumpectomy and radiation did the best. By contrast, the lowest five-year disease free and overall survival was for patients with lumpectomy alone, followed by patients who had mastectomy plus radiation.
But strong selection bias exists with this study. Because women had chemotherapy prior to the surgery, treatment choice likely differed reflecting response to this treatment. (Tumors which show less response to treatment before surgery generally have worse prognosis.) Acknowledging the study limitations, the author notes that a more ideal trial which randomizes women to receive lumpectomy or mastectomy are likely not possible (as few patients would be willing to participate).
The third study (S3-07), looked at the economic burden and complications associated with different surgery options. Researchers from University of Michigan and MD Anderson looked at Medicare claims and private insurance. These researchers accepted past data showing that survival for the different surgery options are generally similar. Yet, they also noted that mastectomy rates are rising. Medical reasons driving mastectomy include genetic syndromes or multifocal disease. Other reasons that have been reported elsewhere include patient fears of recurrence/death and an underestimation of the harms of mastectomy. These researchers want to add considerations of value to the conversation by looking at cost and rates of complications.
Mastectomy plus reconstruction had two times the increased risk of any complication compared to lumpectomy plus radiation. For private insurance the cost of mastectomy plus reconstruction was nearly $90,000. (Note this was nearly double the cost for Medicare patients, who were analyzed separately.) The cost of complications associated with mastectomy and reconstruction was over $10,000. By contrast, women who had a lumpectomy had fewer complications and lower cost.
Dr. Jatoi was the Discussant commenting on these three papers dealing with breast-conserving surgery. All three were observational studies that tell us about associations, but not if the association is due to cause and effect, chance, or confounding bias. Whether or not women who have lumpectomy plus radiation live longer than women who have a mastectomy, it is clear that a smaller surgery is not worse for women.
There have been six randomized trials comparing breast conserving surgery and mastectomy, which found no survival advantage for either surgery option. In 1990, the NCI consensus panel came to the conclusion that breast-conserving surgery was the optimal treatment based on these trials. Since that time the trend in surgery choice has shifted, with breast-conserving surgery initially rising but declining since 2006 as mastectomy rates have increased. Rates of unilateral mastectomies are actually going down in the U.S., but what is driving the increase in mastectomy rates is bilateral mastectomies. Dr. Jatoi concluded that 25 years after the NCI consensus panel, randomized trials and observations studies continue to show that breast-conserving surgery is the optimal choice for most women.
In less formal settings, multiple doctors and researchers repeated some version of what Dr. Susan Love stated bluntly in the Hot Topics session on Wednesday evening: “There is no data to support bilateral mastectomy. Not better in any biological sense. I just don’t get it.”
As a surgeon herself, Love is clear that “surgery is not the answer for breast cancer”. Doing more surgery does not in fact give patients better outcomes.
In reporting the research presented at SABCS, I am clear that not all of the outcomes which patients value have not been captured or discussed. Some women I interact with have said that “symmetry” is an important outcome. And indeed Dr. Love noted that “for surgeons it’s much easier to do a mastectomy versus a cosmetic lumpectomy”. She went even further and said that it’s easier to match two breasts and do a double mastectomy—with the added benefits to surgeons of “getting paid better” with a bigger surgery.
The data shows that women who are eligible for a lumpectomy but choose mastectomy wont’ live longer and they may have higher complications and cost. Women who have a lumpectomy live as long (and possibly longer) as women who have a mastectomy, and the breast-conserving surgery was developed precisely because it’s preferable for women in many ways to removing the whole breast.