Risk factors for uncommon histologic subtypes of breast cancer using centralized pathology review in the Breast Cancer Family Registry

Recognizing invasive breast carcinoma of no special type with medullary pattern

Invasive breast carcinoma of no special type (IBC-NST) with medullary pattern is an uncommon histologic type of invasive breast carcinoma. It is associated with high-grade, poorly differentiated tumor cells that form large sheets of irregular confluent tumor cells associated with a prominent lymphocytic infiltrate. Patients with IBC-NST with medullary pattern are often postmenopausal women with a high body mass index and multiparity. We report the case of a 71-year-old woman who presented for routine screening mammography and breast mass suspicious for malignancy, initially thought to be invasive ductal carcinoma with an associated prominent lymphoid infiltrate. However, it was ultimately diagnosed as IBC-NST with medullary pattern, and radiologic imaging (particularly ultrasound and mammography) along with pathology review were critical in making the diagnosis. We make the case of the importance of radiographic imaging in diagnosing this condition, as the prognosis of IBC-NST with medullary pattern is typically more favorable compared to IBC-NST.

Clinicopathological characteristics and prognosis of breast cancer with special histological types: A surveillance, epidemiology, and end results database analysis

Objectives

To explore the clinicopathological features and prognosis of breast cancer with special histological types.

Materials and methods

The information of breast cancer patients was obtained from the Surveillance, Epidemiology, and End Results (SEER) database (2010–2016). Comparative analyses were performed to explore the difference in clinicopathological characteristics and propensity score matching (PSM) was used to weaken the effects from clinical profiles. Survival analysis was conducted to investigate the prognostic effects from histological types, and the prognostic factors of this group of patients were identified with the univariate COX proportional model.

Results

A total of 242863 breast cancer patients were eligible, of which 230213 individuals were ductal breast cancer (IDC) and 12650 individuals were special breast lesions, respectively. Comparatively, special breast cancer had a lower histological grade, a smaller tumor size, a lower proportion of nodal involvement and distant metastasis, in addition to a higher proportion of triple-negative subtype. The overall prognosis of special histological breast cancer was comparable to IDC, while the survival of HER2 enriched breast cancer was in favor of special breast cancer. With the PSM performance, the prognosis exhibited an inferior profile in the metaplastic breast cancer and was significantly favorable to apocrine, medullary, micropapillary, and papillary breast cancer.

Conclusion

This study revealed that the special histological breast cancer presented distinct clinicopathological characteristics and great heterogeneity in the prognosis among diverse histological subtypes.

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Breast cancer is a heterogenous disease with diverse histological subtypes.

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Special histological breast cancer exhibits distinct clinicopathological profiles.

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Prognosis of special histological breast cancer is profoundly heterogenous.

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Histological subtype is an independent prognostic indicator of breast cancer.

Lobular breast cancer: incidence and genetic and non-genetic risk factors

While most invasive breast cancers consist of carcinomas of the ductal type, about 10% are invasive lobular carcinomas. Invasive lobular and ductal carcinomas differ with respect to risk factors. Invasive lobular carcinoma is more strongly associated with exposure to female hormones, and therefore its incidence is more subject to variation. This is illustrated by US figures during the 1987 to 2004 period: after 12 years of increases, breast cancer incidence declined steadily from 1999 to 2004, reflecting among other causes the decreasing use of menopausal hormone therapy, and these variations were stronger for invasive lobular than for invasive ductal carcinoma. Similarly, invasive lobular carcinoma is more strongly associated with early menarche, late menopause and late age at first birth. As for genetic risk factors, four high-penetrance genes are tested in clinical practice when genetic susceptibility to breast cancer is suspected, BRCA1, BRCA2, TP53 and CDH1. Germline mutations in BRCA1 and TP53 are predominantly associated with invasive ductal carcinoma, while BRCA2 mutations are associated with both ductal and lobular cancers. CDH1, the gene coding for the E-cadherin adhesion protein, is of special interest as mutations are associated with invasive lobular carcinoma, but never with ductal carcinoma. It was initially known as the main susceptibility gene for gastric cancer of the diffuse type, but the excess of breast cancers of the lobular type in CDH1 families led researchers to identify it also as a susceptibility gene for invasive lobular carcinoma. The risk of invasive lobular carcinoma is high in female mutation carriers, as about 50% are expected to develop the disease. Carriers must therefore undergo intensive breast cancer screening, with, for example, yearly magnetic resonance imaging and mammogram starting at age 30 years.

Rare breast cancer subtypes: histological, molecular, and clinical peculiarities

Breast cancer encompasses a collection of different diseases characterized by different biological and pathological features, clinical presentation, response to treatments, clinical behavior, and outcome. On the basis of cell morphology, growth, and architecture patterns, breast cancer can be classified in up to 21 distinct histological types. Breast cancer special types, including the classic lobular invasive carcinoma, represent 25% of all breast cancers. The histological diversity of breast carcinomas has relevant prognostic implications. Indeed, the rare breast cancer group includes subtypes with very different prognoses, ranging from the tubular carcinoma, associated with an indolent clinical course, to metaplastic cancer, whose outcome is generally unfavorable. New approaches based on gene expression profiling allow the identification of molecularly defined breast cancer classes, with distinct biological features and clinical behavior. In clinical practice, immunohistochemical classification based on the expression of human epidermal growth factor receptor 2 and Ki67 is applied as a surrogate of the intrinsic molecular subtypes. However, the identification of intrinsic molecular subtypes were almost completely limited to the study of ductal invasive breast cancer. Moreover, some good-prognosis triple-negative histotypes, on the basis of gene expression profiling, can be classified among the poor-prognosis group. Therefore, histopathological classification remains a crucial component of breast cancer diagnosis. Special histologies can be very rare, and the majority of information on outcome and treatments derives from small series and case reports. As a consequence, clear recommendations about clinical management are still lacking. In this review, we summarize current knowledge about rare breast cancer histologies.

Mucinous breast cancer - clinical characteristics and treatment results in patients treated at the Oncology Centre in Kraków between 1952 and 2002

Aim of the study

To present the characteristics and clinical outcomes in 94 patients with mucinous breast cancer treated at the Oncology Centre in Krakow between 1952 and 2002.

Material and methods

Stage I or II carcinomas were found in 66 patients (69.4%) of the presented group and in the remaining 28 patients (29.8%) stage III disease was diagnosed. In 27 cases regional lymph nodes were involved. All patients had been treated with surgery: mastectomy (90 patients) or breast-conserving treatment (4 patients). Radiotherapy was administered in 14 patients, adjuvant chemo-therapy in 14 patients, and endocrine therapy in 39 patients.

Results

The maximum follow-up was 257 months. Ten-year survival was as follows: 75.7% (overall survival), 82.5% (disease-free survival). During the follow-up, 4 patients developed local recurrence, 5 patients developed metastases. Second primary cancer was found in 8 patients.

Conclusions

The presented results confirm the good prognosis in patients treated for mucinous breast cancer. The diagnosis of early-stage breast cancer based on mammography can allow breast-conserving treatment.

Reproductive risk factors and oestrogen/progesterone receptor-negative breast cancer in the Breast Cancer Family Registry

BACKGROUND

Oestrogen receptor (ER)- and progesterone receptor (PR)-negative (ER-PR-) breast cancer is associated with poorer prognosis compared with other breast cancer subtypes. High parity has been associated with an increased risk of ER-PR- cancer, but emerging evidence suggests that breastfeeding may reduce this risk. Whether this potential breastfeeding benefit extends to women at high risk of breast cancer remains critical to understand for prevention.

METHODS

Using population-based ascertained cases (n=4011) and controls (2997) from the Breast Cancer Family Registry, we examined reproductive risk factors in relation to ER and PR status.

RESULTS

High parity (≥3 live births) without breastfeeding was positively associated only with ER-PR- tumours (odds ratio (OR)=1.57, 95% confidence interval (CI), 1.10-2.24); there was no association with parity in women who breastfed (OR=0.93, 95% CI 0.71-1.22). Across all race/ethnicities, associations for ER-PR- cancer were higher among women who did not breastfeed than among women who did. Oral contraceptive (OC) use before 1975 was associated with an increased risk of ER-PR- cancer only (OR=1.32, 95% CI 1.04-1.67). For women who began OC use in 1975 or later there was no increased risk.

CONCLUSIONS

Our findings support that there are modifiable factors for ER-PR- breast cancer and that breastfeeding in particular may mitigate the increased risk of ER-PR- cancers seen from multiparity.

Risk factors for specific histopathological types of postmenopausal breast cancer in the NIH-AARP Diet and Health Study

Risk factor associations for rare breast cancer variants are often imprecise, obscuring differences between tumor types. To clarify differences, we examined risk factors for 5 histological types of breast cancer in the National Institutes of Health-AARP Diet and Health Study. Risk factor information was self-reported. We followed 192,076 postmenopausal women aged 50-71 years from 1995-1996 through 2006. During that time period, 5,334 ductal, 836 lobular, 639 mixed ductal-lobular, 216 mucinous, and 132 tubular breast cancers were diagnosed. Hazard ratios and 95% confidence intervals were estimated using Cox proportional hazards regression. Heterogeneity was evaluated using case-only logistic regression. The strongest differences were for menopausal hormone therapy (Pheterogeneity < 0.01) and age at first birth (Pheterogeneity < 0.01). Risk of tubular cancer in relation to current menopausal hormone therapy (for current use vs. never use, hazard ratio (HR) = 4.39, 95% confidence interval (CI): 2.77, 6.96) was several times stronger than risk of other histological types (range of HRs, 1.39-1.75). Older age at first birth was unassociated with risk of mucinous (for ≥30 years vs. 20-24 years, HR = 0.62, 95% CI: 0.27, 1.42) or tubular (HR = 1.08, 95% CI: 0.51, 2.29) tumors, in contrast to clear positive associations with lobular (HR = 1.82, 95% CI: 1.39, 2.37) and mixed ductal-lobular (HR = 1.87, 95% CI: 1.39, 2.51) tumors. Differing associations for hormonal factors and mucinous and tubular cancers suggest etiologies distinct from those of common breast cancers.