Size Doesn’t Matter: A discussion on tumor size, treatment & breast conservation

bleicher_rBy Richard J. Bleicher, MD, FACS, Fox Chase Cancer Center/Temple Health

“I’m sorry. Your tumor is too big. You will need a mastectomy.”  These are dreaded words that no one wants to hear when diagnosed with breast cancer.

And until now, you were likely to hear those words if your tumor was over 5 cm, even if you had a generous breast size. So why is that?

As you probably know, about 35 years ago, women were still receiving mastectomies for breast cancers of all sizes. At the time, this was felt to be the safest route to remove all of the tumor and prevent recurrence of the cancer as much as possible. But then in the 1980s researchers began to investigate whether it was possible to remove just the tumor and a margin of normal tissue around it and still have a survival equivalent to those women who underwent a mastectomy.

And so the clinical trials began – comparing lumpectomy to mastectomy. And to be on the safe side, whole-breast radiation was added to the lumpectomy treatment arms of the trials, in an effort to provide additional local control of tumor, by treating the entire breast. Radiation was known already at this point to assist in killing tumor cells, while sparing normal tissue in the appropriate doses. So the trials compared lumpectomy with whole-breast radiation, to mastectomy.

So what did they find? The two treatments are equivalent. But the trials only included women with small tumors, and so the trials included women whose tumors were ≤2 cm, ≤2.5 cm, ≤4 cm, or ≤5 cm, but none of them included women whose tumors were larger than 5 cm.

Now the rule in medicine generally is that if you have research showing treatment benefit in a specific setting, you can’t just extrapolate that benefit to others. (So for instance, if a study shows that a medicine is good for the itchy rash of psoriasis, it doesn’t mean it’s good for the itchy rash from poison ivy and you can’t just assume that. You have to test it and see.) And some data have suggested that as tumors get larger, the risk of it recurring in the breast increases. Hence the concern of doing lumpectomy for tumors over 5 cm. But over the past several years, other data suggests that size doesn’t matter: that the recurrence risk doesn’t drastically increase for larger tumors, even if it does possibly go up a little bit.

Unfortunately, even though it’s many years later, we have had little data to suggest that tumors over 5 cm can still be treated with breast conservation safely. Currently, the medical treatment guidelines still reflect the fact that the trials excluded patients with tumors over 5 cm.

So at Fox Chase Cancer Center, we decided to evaluate that, using one of the largest datasets in the country that’s linked to Medicare claims data. We found, in the largest series to date comprising thousands of women with tumors over 5 cm, that women who have tumors over 5 cm can still undergo lumpectomy and radiotherapy safely. Read more about the study here.

Why is this important? Because while some of us suspected this all along, we now have decent evidence that breast conservation is an option for women with larger tumors if their surgeons deem the tumor resectable from a practical and cosmetic standpoint. Moreover, the guidelines need to change; we should not be telling women that tumors over 5 cm should universally undergo mastectomy.

So size doesn’t matter. Talk to your surgeon about what your options are. And get a second opinion if need be. Those options may be more numerous than you think.


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