Age-dependent growth rate of primary breast cancer

Abstract

Background. Currently, there have been no reports of clear‐cut beneficial effects of regular screening with mammography at a mean screening interval of 2 years in women younger than 50 years of age. It may be that, because of a higher growth rate of breast cancer, more frequent screening is necessary if any effect is to be observed in this age group. However, good quantitative estimates for the growth rate in different age groups are lacking. Methods. The study group consisted of cancers diagnosed in women who participated in a screening program with serial mammography available. The growth rate, expressed as the tumor volume doubling time, was calculated on the assumption of exponential growth. The analysis was based, not only on the increase in tumor volume for cancers with at least two mammograms showing a measurable tumor nucleus shadow (n = 85), but also on censored values, calculated for cancers showing no growth (n = 6) and for cancers showing only a measurable tumor nucleus shadow on the mammogram at diagnosis (n = 109). In calculating these latter growth rates, the density of the breast parenchyma was taken into account. Results. The median volume doubling time of the primary breast cancers diagnosed in women aged 50–70 years was 157 days (95% confidence limits, 121–204 days). This was significantly longer than in women younger than 50 years of age at diagnosis (80 days; 95% confidence limits, 44–147 days). Primary breast cancer in women older than 70 years of age at diagnosis grew even more slowly (median, 188 days; 95% confidence limits, 120–295). Conclusions. To observe a beneficial effect of screening, if any, for women younger than age 50 years, more frequent screening than in the older age group is necessary.

Estimates of Breast Cancer Growth Rate From Mammograms and Its Relation to Tumour Characteristics

“…The estimated average tD of 282 days in this study was in the range of other reported studies (105-327 days) (1)(2)(3)(6)(7)(8)(9)(10)(11)(12) . Previous reporting of tumour growth and histopathological findings are inconsistent and some of these studies use outdated histopathological measures making a direct comparison difficult.…”

“…Previous reporting of tumour growth and histopathological findings are inconsistent and some of these studies use outdated histopathological measures making a direct comparison difficult. Nevertheless, patient age (8,9,11) , axillary lymph node involvement (2,7) and advanced TNM stage (11,12) have been shown to correlate with tD. Kusama et al and Kuroshi et al both found that tumour volume doubling time correlated with survival (9,11) .…”

“…Several studies have estimated the volume doubling time of breast cancers based on mammograms (1,2,(5)(6)(7)(8)(9)(10)(11) , however, few have correlated tD with histopathological characteristics (2,7,(9)(10)(11) . To the best of the authors' knowledge, only one study based on ultrasound has correlated tD with tumour characteristics such as the oestrogen receptor (ER), the progesterone receptor (PR), the human epidermal growth factor receptor 2 (HER2) and Ki-67 expression (12) .…”

Short-term effects of night shift work on breast cancer risk: a cohort study of payroll data

“…Age, age at birth of first child, number of children, a family history of breast cancer or ovarian cancer, and hormone replacement therapy may have distinct effects on breast cancer subtypes (42)(43)(44). Therefore, we divided the potential confounders into two sets of covariates: (A) age (<40, 40-44, 45-49, and every second year from age 50), age at birth of the first child (<20, 20-29, ≥30, no children), number of births (0, 1, 2, 3, ≥4), family history of breast cancer or ovarian cancer (0, ≥1, no information), hormone replacement therapy (no, yes); and (B) calendar year (each year 2007-2012), oral contraceptives (no, yes), other sex hormones (no, yes), medication related to alcoholism, (no, yes), mammography screening attendance (invited but not screened, invited and screened, not invited), and highest family educational level at the first registration of work (unspecified, primary and secondary school, advanced level education, vocational education, undergraduate and bachelor degree, higher education, and no information on education).…”

The growth law of primary breast cancer as inferred from mammography screening trials data

“…possiblY. not representatixe g roups of patients (Gershon-Cohen et al 1963: Heuser et al 1979: Foumier et al 1980: Peer et al 1993: Spratt et al 1993. Several putative lawxs for tumour growth hasve been proposed.…”