In a nutshell
The authors aimed to distinguish whether the characteristics of breast cancer could depend on the focality of the tumor.
Some background
Breast cancer can be characterized as 'unifocal', 'multifocal and 'multicentric'. This refers to the number of areas in which the cancer can be found (focality); unifocal being one tumor, multifocal being more than one tumor that originated from the same original tumor and multicentric being more than one tumor separated by normal breast tissue.
Previous studies show that multicentric tumors may be more aggressive than multifocal and unifocal tumors. The link between tumor focality and prognosis (outlook), however, is not well understood.
Methods & findings
A total of 1,495 patients with invasive breast cancer (tumor can spread) were evaluated. 82.3% of these women had unifocal tumors, 11.3% had multifocal tumors and 6.4% had multicentric tumors.
Of all the women with a multicentric tumor, 49% were younger than 50. 62% of them had lymph node positivity (cancer cells within their lymph nodes – small organs that are part of the immune system). Those with a multicentric tumor were twice as likely to have lymph node positivity than those with a multifocal tumor. 20% also had lobular invasion (cancer affects particular parts of the breast tissue).
On the other hand, multifocal tumors were more likely to progress to ductal carcinoma (cancer cells in the milk ducts of the breast). This occurred in 34% of women with multifocal tumors and only 18% of those with unifocal tumors. Both the primary and secondary tumor within women with multifocal cancer were smaller in size than those with multicentric cancer.
Overall, multifocal and multicentric tumors are biologically distinct diseases with individual clinical characteristics.
The bottom line
The authors concluded that multicentric tumors are more aggressive, more likely to be associated with cancer in the lymph nodes and more likely to be larger in size than multifocal tumors.
The fine print
This study did not analyse patient survival and so the long-term outcome of these findings is unclear.
Published By :
Annals of Surgical Oncology
Date :
Mar 25, 2015
