Patients with lobular breast cancer were found to be significantly positively associated with having a father diagnosed with cancer, especially prostate cancer, according to a recent Swedish study published in the journal BMC Cancer.
Breast cancer can be broadly categorized into - i) in-situ carcinoma where tumor cells are localized and have not spread into surrounding tissue and ii) invasive cancer. The in-situ type of breast cancer is further classified into either ductal or lobular depending upon their growth patterns and tissue features. Lobular breast cancer is a common form of breast cancer more often found in both breasts.
AdvertisementEarlier studies have found positive associations between lobular breast cancer and family history of cancer, especially family history of breast cancer in first-degree relatives. Studies have also found that the familial association of lobular breast cancer could mainly be due to patients with BRCA2 gene mutation or the occurrence of hereditary diffuse gastric cancer. However, not much information is available on familial cancer patterns in lobular breast cancer.
So, Carolina Ellberg and Hakan Olsson from the Clinical Sciences, Lund University, undertook a study on 1676 breast cancer patients with the aim to identify new hereditary patterns predisposing to cancer by focusing on patients with lobular breast cancer and cancer in their first-degree relatives. Breast cancer patients consisted of 41 percent invasive ductal carcinoma, 8 percent of invasive lobular carcinoma, 2 percent of medullary carcinoma, 1 percent of mucinous carcinoma, and 48 percent of adenocarcinoma. The overall median age at diagnosis was 56 years with a range between 23 and 89 years.
Results showed that:
• Patients with lobular breast cancer were found to be significantly positively associated with having a father diagnosed with cancer.
• Ductal breast cancer was associated with having a mother diagnosed with cancer.
• The five most common diagnoses in fathers with cancer with a daughter with lobular breast cancer were prostate cancer (6 percent), leukemia (4 percent), lung cancer (1 percent), lower gastrointestinal tract cancer (3 percent), stomach cancer (2 percent) and sarcoma (2 percent).
• The occurrence of having a father with prostate cancer for lobular breast cancer patients was higher in the younger patient group, and was still high but lost statistical significance in the older patient group.
• The median age at cancer diagnosis for the fathers of the lobular breast cancer patients was 70 years. The median age of the father at their daughter's birth was 32 years. It does not necessarily represent age at first child, since the patients diagnosed with lobular breast cancer may not be the oldest children.
These results showed an association between lobular breast cancer and cancer in the father, and which was seemingly independent of classical breast cancer heredity. The association with a father diagnosed with cancer also remained after removing prostate cancer, indicating that different types of tumors in the father are associated with lobular breast cancer in the daughter.
'That there might be a genetic cause is strengthened by the fact that the younger lobular breast cancer patients had an increased risk of having a father with prostate cancer, compared to the other breast cancer subtypes', say the researchers.
There was no difference in cancer diagnoses in second- and third-degree relatives on the paternal or maternal side of the lobular breast cancer cases. This means that the association is not connected to an imbalance in number of cancer diagnoses on the paternal side. It also indicates that it may only be related to the father, or inherited from the father.
The authors concluded that 'Our study has identified a possible father-daughter inheritance pattern in lobular breast cancer, independent of previous family history of breast cancer. These findings need to be validated in other materials in order to later elucidate the possible mechanism behind the association'.
Source: Ellberg C, Olsson H. Breast cancer patients with lobular cancer more commonly have a father than a mother diagnosed with cancer. BMC Cancer. 2011 Nov 28;11:497.