MONDAY, April 10, 2006 (HealthDay News) -- Women diagnosed with early localized breast cancer typically receive treatment based on how likely their doctor thinks it is that the tumor will spread.
Now, emerging data sheds a new light on those most dangerous tumors and challenges the conventional wisdom on breast cancer care.
The study results show that patients with one form of breast cancer, called lobular carcinoma in situ (LCIS), are at higher risk of developing advanced tumors than previously thought.
In addition, women with ductal carcinoma in situ (DCIS) who are under 50 years old, black or Hispanic are also at increased risk of developing advanced-stage invasive tumors, the researchers reported in the May 15 issue of Cancer.
DCIS and LCIS are both early cancers that have not yet spread to adjacent tissue. The diagnosis of DCIS and LCIS has been increasing sevenfold since 1980, most likely because of an increase in mammograms and breast biopsies.
"We are detecting breast cancer earlier, which is good, [but] without really knowing what clear clinical recommendations we can give patients," said lead researcher Dr. Christopher I. Li, of the Fred Hutchinson Cancer Research Center in Seattle.
According to Li, his team "looked at women who had developed early breast cancer and followed them to see which ones developed invasive breast cancer."
The researchers collected data on nearly 38,000 DCIS and 4,500 LCIS patients from 1988 to 2002. Using that data, they identified risk factors for invasive disease and the pattern of invasive disease of both DCIS and LCIS.
"We found that patients who had LCIS had a higher risk of developing invasive cancer than previously thought, particularly for cancer in the same breast that their in situ cancer was diagnosed," Li said.
The researchers also found that women with the most common in situ cancer, DCIS, who were 50 or younger or who were black or Hispanic, were more likely to be diagnosed with more advanced stage breast cancer over time, Li said.
These findings may influence how breast cancer patients are treated, Li said. "Our results suggest that LCIS, which are typically not aggressively treated, may warrant more definitive treatment than they are getting today," he said.
"One of the reasons that the rates of invasive cancer are lower among DCIS patients is that they do typically get definitive treatment. So perhaps definitive treatment for LCIS patients would [also] be beneficial for them," Li said.
One expert thinks these findings are too preliminary to change treatment, however.
Currently, women diagnosed with LCIS don't receive therapy, but their condition is monitored with mammograms, said Dr. Len Lichtenfeld, the deputy chief medical officer at the American Cancer Society. "But it does look like LCIS is potentially a pre-malignant condition," he said.
Because this study is a retrospective study, it is "not the type of research upon which doctors should base a change in treatment," he added. "Doctors should being saying 'We need to re-examine this issue, and we need to do more in-depth analysis.' "
However, given these data, Lichtenfeld said that women diagnosed with LCIS should have their breasts examined more often. In addition, the data indicate that patients who are under 50 years old, black or Hispanic, and diagnosed with either type of early breast cancer need closer monitoring, he said.
Lichtenfeld noted that current guidelines recommend that women with either LCIS or DCIS take the drug tamoxifen to reduce their risk of invasive breast cancer. "Tamoxifen is an effective risk-reduction strategy," he said.
"If you have either of these conditions, there are guideline recommendations that you should consider tamoxifen, and it's something you need to discuss with your doctor," Lichtenfeld said.
More information
For more on breast cancer, head to the National Cancer Institute.
