eCG concentrations, luteal structures, return to cyclicity, and postabortion fertility in embryo transfer recipient mares.

The present study characterizes the relationship between the levels of eCG, ovarian morphology, resumption of cyclicity, and fertility in postaborted embryo transfer recipient mares. A total of 32 pregnant recipient mares carrying a male fetus were aborted at approximately 65 days of gestation by single transcervical administration of cloprostenol. In addition, 25 gestation age-matched mares were used as nonaborted controls. The concentration of progesterone, but not of eCG, differed significantly between controls and aborted mares 48 hours after abortion. Of treated mares, 84.4% (27 of 32) expelled the fetus within 48 hours of treatment. The eCG concentration and the number of supplementary luteal structures were lower in mares aborted in November (equivalent to May in Northern Hemisphere) than in January. A total of 6.2%, 37.5%, and 56.2% of the mares entered anestrus, ovulated normally, and had 1 to 2 consecutive anovulatory cycles, respectively. The mean interval from abortion to the first ovulation was 28.5 ± 3.3 days (range, 5-65 days). The correlation between the levels of eCG at abortion and the interval to the first ovulation was poor (r = 0.38; P = 0.03). Of aborted mares, 90% (18 of 20) were reused and became pregnant after embryo transfer at a mean of 57.6 ± 4.4 days after abortion (range, 19-103 days) and eCG concentration of 0.9 ± 0.3 IU/mL (range, 0.1-3.6 IU/mL). In conclusion, the levels of eCG at the time of abortion were extremely variable and did not correlate well with the number of luteal structures or the interval from abortion to the first ovulation.

The effect of the interval from PGF treatment to ovulation on embryo recovery and pregnancy rate in the mare.

The objective of this study was to determine the effect of the interval from induced luteolysis to ovulation on fertility of mares from two different farms. At farm 1, 215 mares were inseminated with frozen/thawed semen during 513 estrous cycles over seven consecutive breeding seasons. Estrus was induced with analogues of PGF2α in 179 cycles. At farm 2, 375 embryo flushings were performed in 65 donor mares inseminated with fresh semen; of which, 327 were performed following artificial insemination after PGF-induced luteolysis. In both farms, the intervals from PGF treatment to ovulation (ITO) data were divided into three interval groups: less than 6 days, 6 to 8 days, and greater than 8 days. A mixed regression model was created to determine the effect of different factors on the pregnancy rate (PR) and embryo recovery rate (ERR). Of all factors analyzed, the ITO was the only one that significantly influenced the PR and ERR (P < 0.05). In farm 1, the PR of mares with an ITO of less than 6 days, 6 to 8 days, and greater than 8 days was 26.6%, 39.4%, and 55.9%, respectively (P = 0.01). The PR for mares inseminated after spontaneous luteolysis (without PGF) was 42.5%. In farm 2, the ERR of donor mares for the same ITO groups was 55.0%, 62.6%, and 73.7%, respectively (P = 0.02). The ERR for mares flushed after a previous spontaneous estrus was 75.0%. In conclusion, the ITO had a significant effect on the PR and ERR in the mare. Fertility was reduced as the ITO became shorter.

Analysis of interval cancers observed in an Italian mammography screening programme (2000-2006).

PURPOSE: The purpose of this study was to assess the interval cancer (IC) proportional incidence and review IC cases observed in an Italian mammography screening programme during 2000-2006. MATERIALS AND METHODS: ICs were identified through linkage of a screening database with the local cancer registry and hospital discharge records to calculate proportional (observed/expected) incidence. Negatively reported mammograms preceding ICs underwent blind review (randomly mixed with negative controls in a 2:1 ratio) by three expert radiologists and classified according to European guidelines criteria (OC=occult, MS=minimal sign, SE=screening error) according to majority report. Proportional IC incidence and rate of reviewed IC classified as SE were compared with European guideline standards. RESULTS: Proportional IC incidence was 10.8% in the first and 40.0% in the second year of the interval (European standard=30% or 50%, respectively). Sensitivity estimate for the 2-year interval was 74.6%. ICs were reviewed as SE, MS or OC in 15.0%, 14.0% or 71.0% of cases, respectively. Corresponding review results for negative controls were 7.0%, 25.0% or 68.0%, respectively. Positive predictive value for IC was 51.7% for SE and 21.8% for MS reporting category, respectively (p=0.008). European standard (<20% reviewed as SE) was reached. CONCLUSIONS: The study shows that the sensitivity of the mammography programme was good, complying with European guideline recommendations. Assessment of IC-based early indicators of screening efficacy is feasible in a current screening programme and should become a routine procedure.

Mastectomy rates are decreasing in the era of service screening: a population-based study in Italy (1997-2001).

We enrolled all 2162 in situ and 21 148 invasive cases of breast cancer in 17 areas of Italy, diagnosed in 1997-2001. Rates of early cancer increased by 13.7% in the screening age group (50-69 years), and breast conserving surgery by 24.6%. Advanced cancer rates decreased by 19.4%, and mastectomy rates by 24.2%. Service screening did not increase mastectomy rates in the study population.

Screen-detected vs clinical breast cancer: the advantage in the relative risk of lymph node metastases decreases with increasing tumour size.

Screen-detected (SD) breast cancers are smaller and biologically more indolent than clinically presenting cancers. An often debated question is: if left undiagnosed during their preclinical phase, would they become more aggressive or would they only increase in size? This study considered a registry-based series (1988-1999) of 3329 unifocal, pT1a-pT3 breast cancer cases aged 50-70 years, of which 994 were SD cases and 2335 clinical cases. The rationale was that (1) the average risk of lymph node involvement (N+) is lower for SD cases, (2) nodal status is the product of biological aggressiveness and chronological age of the disease, (3) for any breast cancer, tumour size is an indicator of chronological age, and (4) for SD cases, tumour size is specifically an indicator of the duration of the preclinical phase, that is, an inverse indicator of lead time. The hypothesis was that the relative protection of SD cases from the risk of N+ and, thus, their relative biological indolence decrease with increasing tumour size. The odds ratio (OR) estimate of the risk of N+ was obtained from a multiple logistic regression model that included terms for detection modality, tumour size category, patient age, histological type, and number of lymph nodes recovered. A term for the detection modality-by-tumour size category interaction was entered, and the OR for the main effect of detection by screening vs clinical diagnosis was calculated. This increased linearly from 0.05 (95% confidence interval: 0.01-0.39) in the 2-7 mm size category to 0.95 (0.64-1.40) in the 18-22 mm category. This trend is compatible with the view that biological aggressiveness of breast cancer increases during the preclinical phase.