The study reviewed here tries to offer more information on whether women who have mastectomy to remove early-stage breast cancer (stage I or stage II) can benefit from radiation therapy after surgery. Unfortunately, there isn't a clear answer.
Radiation therapy is used after lumpectomy to remove early-stage breast cancer to lower the risk of the cancer coming back (recurrence). Research has shown that lumpectomy followed by radiation therapy is a good alternative to mastectomy for many women.
Still, many women choose to have mastectomy instead of lumpectomy. Because mastectomy removes the whole breast (as opposed to lumpectomy which removes only the cancer tumor and a portion of tissue around it), many women who have mastectomy don't have radiation therapy after surgery. But if the cancer has spread to the underarm lymph nodes, cancer experts have recommended that radiation therapy be considered after mastectomy:
Recommendations about using radiation therapy after mastectomy are based on studies done from 1964 to 1984. Since that time, breast cancer care has improved. We now have earlier diagnosis, better surgery methods, and better approaches to treatment. Because of advances in breast cancer care, researchers wanted to look at recurrence risk after mastectomy in more recent years and how much lymph node involvement affected that risk.
The researchers looked at the medical records of 1,019 women diagnosed with stage I or stage II (early-stage) breast cancer between 1997 and 2002. All the women had mastectomy and had from zero to three lymph nodes involved:
Most of the women (77%) got chemotherapy, hormonal therapy, or both after mastectomy. None of the women had radiation therapy after surgery.
After about 10 years, only 2.3% of the women had a breast cancer recurrence after mastectomy. The risk of recurrence seemed to be somewhat linked to the number of positive lymph nodes:
The number of women with three positive nodes was too small to analyze.
The very small difference in recurrence risk between women with zero positive lymph nodes and women with one positive node wasn't statistically significant, which means it could be due to chance and not because of the difference in the number of positive lymph nodes.
The recurrence risk for women with two positive lymph nodes was significantly higher than recurrence risk for women with one or zero positive nodes, which means the difference was likely due to the larger number of positive nodes. Still, the 7.9% risk of recurrence is much lower than the 20% to 25% recurrence rates found in earlier studies looking at recurrence risk after mastectomy.
Recurrence risk after mastectomy also was significantly higher for women age 40 and younger compared to women who were older than 40.
Because the risk of recurrence was lower in this study than in older studies, the researchers suggested that routinely giving radiation therapy after mastectomy to remove early-stage breast cancer to women older than 40 who had zero to three positive lymph nodes may not make sense. It does seem clear that radiation therapy after mastectomy is very important for women younger than 40 with positive lymph nodes.
Other breast cancer experts feel that more research is needed before changing the recommendations about using radiation therapy after mastectomy to remove early stage-breast cancer in women with one to three positive lymph nodes.
If you've been diagnosed with early-stage breast cancer, you and your doctor will decide on the type of surgery -- lumpectomy or mastectomy -- that makes the most sense for you. If lumpectomy is your choice, it's very likely that your doctor will recommend radiation therapy after surgery. If mastectomy is your choice, you and your doctor will consider a number of factors, including:
that can influence your risk of recurrence as you decide if radiation therapy after surgery makes sense for you and your unique situation.
ST. LOUIS (MedPage Today) -- Many women who undergo mastectomy for early-stage breast cancer may not benefit from radiotherapy, a retrospective study suggested.
Among those who had stage I or II disease with spread to no more than three lymph nodes and who did not undergo radiation therapy, the overall locoregional recurrence rate was just 2.3% at 10 years, according to Ranjna Sharma, MD, of the University of Texas M.D. Anderson Cancer Center in Houston.
The recurrence rate was not significantly different between patients with one lymph node metastasis and those with no nodal involvement (3.3% versus 2.1%, P=0.30), Sharma reported at the Society of Surgical Oncology Annual Cancer Symposium here.
Compared with patients with no positive lymph nodes, those with two had a significantly higher, but still relatively low, rate of recurrence at 10 years (7.9%, P=0.003).
According to senior author Henry Kuerer, MD, PhD, also of M.D. Anderson, the findings call into question national guidelines that recommend "strong consideration" for radiotherapy in women undergoing mastectomy for early-stage disease with one to three positive lymph nodes.
There is consensus that women with more advanced stage III or IV disease, or those with four or more nodal metastases, should receive postmastectomy radiation, he said in an interview.
But use of radiation in women with stage I or II disease with one to three positive nodes, who make up about 90% of those who undergo mastectomy, has been a source of controversy for several years.
"We would suggest that the patients and their doctors look at the patients' individual risk and not just routinely give radiation therapy," he said, noting that younger age and the presence of extracapsular extension and extensive lymphatic vascular invasion are all risk factors for recurrence.
Lori Pierce, MD, a radiation oncologist at the University of Michigan in Ann Arbor, agreed, in an interview with MedPage Today, that treatment should be individualized but said a retrospective study of this size cannot be used to answer the question about whether women with one to three positive nodes should receive postmastectomy radiation.
She pointed to the small number of patients in the study that had one to three positive lymph nodes, which may not be representative of a larger sample.
"Much larger retrospective studies can give us some information, but the gold standard is to do a prospective study," said Pierce, a spokesperson for the American Society of Clinical Oncology.
The use of radiotherapy in these patients increased after the release of the 2007 guidelines from the National Comprehensive Cancer Network, Kuerer said.
The guidance was made partially on the findings of a 2005 meta-analysis looking at randomized trials conducted between 1964 and 1984. The analysis determined that postmastectomy radiation in these women resulted not only in about a 66% reduction in locoregional recurrence compared with no radiation, but also about a 5% survival advantage.
The overall recurrence rate in those studies ranged from 20% to 25%, much higher than observed in the present day, Kuerer said.
So, to better understand the patients' risks in an era of earlier detection, better surgical techniques, and improved systemic therapies, Kuerer and his colleagues retrospectively reviewed the records of 1,019 women (median age 54) from the prospective Breast Cancer Management Database at M. D. Anderson.
All had T1 or T2 tumors and were treated with margin-negative mastectomy and sentinal lymph node biopsy or axillary dissection from 1997 to 2002. None received preoperative chemotherapy or postoperative radiotherapy.
About three-quarters (77%) received chemotherapy, hormone therapy, or both after the operation.
Most of the women (74%) did not have any lymph node metastases. The rest had one (17%), two (7%), or three (2%).
Overall, a locoregional recurrence occurred in only 2.3% of patients after a median of 3.8 years.
Although the rate of recurrence at 10 years progressively increased with each positive lymph node, there was no significant difference between patients with no positive nodes and those with one.
There were not enough patients with three positive nodes to draw any conclusions, the researchers determined.
Aside from nodal involvement, age was the only significant predictor of recurrence in a multivariate analysis. Patients 40 and younger had a significantly higher 10-year rate than older women (11.1% versus <3%, P<0.0001).
Although the current analysis included data from a single center, Kuerer said he believes the use of standardized therapies and strict guidelines at M.D. Anderson make the results generalizable beyond this specific patient group and relevant to the ongoing debate about the use of postmastectomy radiation in women with one to three nodal metastases.
He noted that U.S. clinicians attempted to initiate a randomized trial in the late 1990s to address the question but had to abandon it because of slow patient accrual.
The randomized SUPREMO trial, primarily in the U.K., is currently enrolling patients but results may not be available for a decade, Kuerer said.
In the meantime, he said he thinks studies like the current analysis will provide useful information for clinicians and patients to consider.
Pierce, who was the principal investigator of the stalled U.S. trial, said the guidelines calling for strong consideration of postmastectomy radiation in women with one to three positive nodes should remain unchanged for the time being.
She said patients should meet with a radiation oncologist for a discussion of the pros and cons of radiation that would include an assessment of their individual tumor characteristics and risk factors.
Some women may have a low risk of recurrence and choose to forego radiation, but others, such as those with angiolymphatic invasion, probably should be treated, Pierce said.
"I think the importance here is to individualize treatment for the patients with one to three positive nodes."
Kuerer and Sharma did not make any financial disclosures.
Primary source: Society of Surgical Oncology's Annual Cancer Symposium Source reference: Sharma R, et al "Present day locoregional recurrence rates (LRR) in patients with T1 and T2 breast cancer (BC) with zero and one to three lymph node (LN) metastases following mastectomy without radiation" SSO 2010; Abstract 47.
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