There seems to be an interest in a maternal age effect

Some papers have found differing maternal age effects in a daughter's risk of breast cancer. Here is one that claims that a daughter's risk rises with maternal age. I have found great differences in the findings in this regard. Some research have found a U shape some a J shape. It does seem that increased maternal and paternal ages have an effect on the risk for non-familial breast cancer.

Maternal age, parity, and pregnancy estrogens
Journal Cancer Causes and Control
Publisher Springer Netherlands
ISSN 0957-5243 (Print) 1573-7225 (Online)
Subject Biomedical and Life Sciences
Issue Volume 1, Number 2 / September, 1990
Category Research Papers
DOI 10.1007/BF00053162
Pages 119-124
SpringerLink Date Thursday, November 04, 2004

Maternal age, parity, and pregnancy estrogens
Kelly Panagiotopoulou, Klea Katsouyanni, Eleni Petridou, Yannis Garas, Anastasia Tzonou and Dimitrios Trichopoulos

Received: 29 March 1990 Accepted: 11 June 1990

Total estrogens (TE), estradiol (E2), estriol (E3), and human placental lactogen (hPL) were determined by radioimmunoassay in the blood of 126 pregnant women during their 26th and 31st weeks of pregnancy and the results were studied in relation to maternal age and parity. Total estrogens and E2 were lowest among the youngest women (<20 years) and highest among women aged 20–24 years, whereas older women (25 + years) had, on the average, intermediate values. For E3 the pattern was qualitatively similar to that of TE and E2 but less striking, and no maternal age pattern was evident with respect to hPL. Within maternal age groups, TE and E2 were higher among women in the first, than among those in their second, full-term pregnancy; the difference was about seven percent for TE (P=0.14) and about 14 percent for E2 (P=0.05). No parity patterns were evident with respect to E3 and hPL. There were fairly strong correlations between the determinations of the same hormone in the same woman during the 26th and 31st weeks of pregnancy; Pearson correlation coefficients were 0.60 for TE, 0.78 for E2, 0.60 for E3, and 0.72 for hPL. Since the risk of breast cancer increases apparently monotonically with maternal age at birth, the present data are equivocal with respect to the hypothesis linking levels of pregnancy estrogens to risk of breast cancer in the offspring. However, the data are compatible with hypotheses linking excessive pregnancy-estrogen exposure to conditions more common among first-born individuals, including testicular cancer and cryptorchidism.
Key words Breast neoplasms - estrogens - maternal age - parity

Drs Panagiotopoulou, Katsouyanni, Petridou, Garas, and