Saturday, May 13, 2006

Important trend in breast cancer

There was a very important piece in the New York Times on adjuvant breast cancer treatment trends.

This is another post that's not really Plastic Surgery per se, but overlaps with our role with breast cancer reconstruction. Most women with invasive breast cancer are given chemotherapy, and in general if was a small tumor that had favorable characteristics and involved no (or few) axillary lymph nodes they traditionally received a two drug chemotherapy regimen (Adriamycin & Cytoxan). In contrast women with larger tumors, those with aggressive cellular characteristics, presentation in their 30's, and multiple (or palpable) axillary lymph node metastasis would get a third drug (usually Taxol) added which adds a lot of morbidity for the patient.

As with sentinel lymph node techniques which have decreased the number of women receiving axillary disections and the resultant 8-30% rates of lyphedema (arm swelling from disruption of lymphatic drainage), we're now parsing the data to figure out who can receive less or even no chemotherapy. The important subgroup that is being considered for this is those with estrogen (ER) or progesterone (PR) receptors present on the tumor.

The simple way to think about breast cancer (or any cancer) is that the more normal regulatory processes a cancer cell maintains, the more areas we have have to attack it with chemotherapy, immunotherpay, or hormone manipulation. An ER/PR+ tumor allows us to block the hormone binding sites and potentially induce programmed cell death (apoptosis) using drugs like .Tamoxifen or Arimidex. These kinds of drugs have few day to day side effects, but do appear to slightly increase other things like cervical cancer and incidence of blood clots. The relative risk of those side effects however, is largely outweighed by their reduction in breast cancer recurrence. Women with these ER or PR tumors seem to have similar or improved disease specific mortality irrespective of their chemotherapy when some epidemiologists retrospectively reviewed the data & is what's gotten us interested in this.

We're left with the interesting possibility of perhaps excluding chemotherapy for many women which would be a revolution in contemporary oncology and of tremendous benefit to our patients. Clinical trials of this strategy are being drawn up to give us data on this

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