Mastitis - Breast Cancer

Breast Cancer

Breast cancer may coincide with or mimic symptoms of mastitis. Only full resolution of symptoms and careful examination are sufficient to exclude the diagnosis of breast cancer.

Lifetime risk for breast cancer is significantly reduced for women who were pregnant and breastfeeding. Mastitis episodes do not appear to influence lifetime risk of breast cancer.

Mastitis does however cause great difficulties in diagnosis of breast cancer and delayed diagnosis and treatment can result in worse outcome.

Breast cancer may coincide with mastitis or develop shortly afterwards. All suspicious symptoms that do not completely disappear within 5 weeks must be investigated.

Breast cancer incidence during pregnancy and lactation is assumed to be the same as in controls. Course and prognosis are also very similar to age matched controls. However diagnosis during lactation is particularly problematic, often leading to delayed diagnosis and treatment.

Some data suggests that noninflammatory breast cancer incidence is increased within a year following episodes of nonpuerperal mastitis and special care is required for followup cancer prevention screening. So far only data from short term observation is available and total risk increase can not be judged. Because of the very short time between presentation of mastitis and breast cancer in this study it is considered very unlikely that the inflammation had any substantial role in carcinogenesis, rather it would appear that some precancerous lesions may increase the risk of inflammation (hyperplasia causing duct obstruction, hypersensitivity to cytokines or hormones) or the lesions may have common predisposing factors.

A very serious type of breast cancer called inflammatory breast cancer presents with similar symptoms as mastitis (both puerperal and nonpuerperal). It is the most aggressive type of breast cancer with the highest mortality rate. The inflammatory phenotype of IBC is thought to be mostly caused by invasion and blocking of dermal lymphatics, however it was recently shown that NF-κB target genes activation may significantly contribute to the inflammatory phenotype. Case reports show that inflammatory breast cancer symptoms can flare up following injury or inflammation making it even more likely to be mistaken for mastitis. Symptoms are also known to partially respond to progesterone and antibiotics, reaction to other common medications can not be ruled out at this point.