Differences in clinicopatholgic characteristics and risk of mortality between the triple positive and ER+/PR+/HER2- breast cancer subtypes

The inhibitory effect of trastuzumab on BT474 triple‑positive breast cancer cell viability is reversed by the combination of progesterone and estradiol

Breast cancer expressing the estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER2) is known as triple-positive (TPBC). TPBC represents 9-11% of breast cancer cases worldwide and is a heterogeneous subtype. Notably, TPBC presents a therapeutic challenge due to the crosstalk between the hormonal (ER and PR) and HER2 pathways. Patients with TPBC are treated with trastuzumab (TTZ); however, several patients treated with TTZ tend to relapse. The present study aimed to investigate the effect of the PR on inhibitory effect of TTZ on cell viability. BT474 cells (a model of TPBC) and BT474 PR-silenced cells were treated with either TTZ, progesterone (Pg), the PR antagonist mifepristone (RU486) or estradiol (E2) alone or in combination for 144 h (6 days). Cell viability assays and western blotting were subsequently performed. The results showed that Pg and E2 interfered with the inhibitory effect of TTZ on cell viability and this effect was potentiated when both hormones were combined. Pg was revealed to act through the PR, mainly activating the PR isoform B (PR-B) and inducing the protein expression levels of CDK4 and cyclin D1; however, it did not reactivate the HER2/Akt pathway. By contrast, E2 was able to increase PR isoform A (PR-A) expression, which was inhibited by Pg. Notably, in most of the experiments, RU486 did not antagonize the effects of Pg. In conclusion, Pg and E2 may interfere with the inhibitory effect of TTZ on cell viability through PR-B activation and PR-A inactivation.

Disease characteristics and mortality among Asian women with breast cancer

BACKGROUND

Asian women with breast cancer are often studied in aggregate, belying significant intragroup diversity. The authors sought to examine differences in breast cancer characteristics and outcomes among Asian women.

METHODS

Asian, non-Hispanic Black, Hispanic, and non-Hispanic White women aged 18 years and older who were diagnosed with breast cancer from 1990 to 2016 were identified in the Surveillance, Epidemiology, and End Results 18 database. Asian patients were subclassified as Chinese, Japanese, Korean, Filipino, Vietnamese, South Asian (Asian Indian or Pakistani), Southeast Asian (SEA, i.e., Cambodian, Laotian, Hmong, or Thai), or other Asian. Unadjusted overall survival (OS) and cancer-specific survival (CSS) were estimated using the Kaplan-Meier method. Cox proportional hazards models were used to estimate adjusted OS and CSS.

RESULTS

In total, 910,415 women were included (Asian, n = 63,405; Black, n = 92,226; Hispanic, n = 84,451; White, n = 670,333). Asian women had higher rates of human epidermal growth factor receptor 2 (HER2)-positive disease compared with White women (18.7% vs 13.8%) and had the highest 10-year unadjusted OS and CSS among all racial/ethnic groups (all P < .001). SEA women had the highest rates of stage IV disease at presentation, whereas Japanese women had the lowest rates (5.9% vs 2.7%; P < .001). Japanese women had the highest 10-year unadjusted CSS (89.4%; 95% confidence interval, 88.7%-90.1%) of any distinct Asian group, whereas SEA women had the worst unadjusted CSS (78%; 95% confidence interval, 74.1%-81.3%; P < .001). After adjustment, SEA women had the worst OS of any Asian group and were the only Asian group without improved OS compared with White women (reference category; P = .08).

CONCLUSIONS

Breast cancer characteristics and outcomes vary significantly among Asian women. Future research should consider disaggregation by country or region of origin to identify subgroups that are at risk for worse outcomes than aggregated data may suggest.

LAY SUMMARY

Asian women with breast cancer are frequently studied as a single entity. However, Asian ethnic groups differ greatly by country of origin, genetic ancestry, disease frequency, socioeconomic status, patterns of immigration, as well as dietary and cultural practices. Women of different Asian ethnicities vary significantly with regard to cancer characteristics, such as mortality and tumor subtype. Future research should disaggregate these populations to better understand, treat, and counsel Asian patients with breast cancer.

Poor-Prognosis Metastatic Cancers in Adolescents and Young Adults: Incidence Patterns, Trends, and Disparities

Background

For adolescents and young adults (AYAs, aged 15-39 years) with cancer, metastatic disease at diagnosis is the strongest predictor of mortality, but its associations with age and sociodemographic factors are largely unexplored.

Methods

Using Surveillance, Epidemiology, and End Results Program data from 2000 to 2016, we collected incident cases of poor-prognosis metastatic cancer (5-year survival < 50%) and compared the proportion, incidence, time trends, and incidence rate ratios for race and ethnicity, sex, and socioeconomic status among AYAs, middle-aged adults (aged 40-64 years) and older adults (aged 65-79 years).

Results

From 2000 to 2016, a total of 17 210 incident cases of poor-prognosis metastatic cancer were diagnosed in AYAs, 121 274 in middle-aged adults, and 364 228 in older adults. Compared with older patients, the proportion of AYAs having metastatic disease was equivalent or substantially lower in nearly every site except stomach and breast cancers, which were statistically significantly higher for AYAs compared with middle-aged and older adults (stomach: 57.3% vs 46.4% and 39.5%; breast: 6.6% vs 4.4% and 5.6%, respectively; 2-sided P < .001 for all comparisons). Incidence rates rose significantly faster among AYAs for breast, stomach, and kidney cancers and among AYAs and middle-aged adults for colorectal cancer. Markedly higher incidence rate ratios were noted for AYA racial and ethnic minorities with breast, stomach, and especially kidney cancer, where only non-Hispanic Black AYAs were at considerably higher risk. For most sites, incidence rate ratios were higher among male patients and individuals of low socioeconomic status across age groups.

Conclusions

For most cancers, AYAs are not more likely to present with metastases than middle-aged and older adults. Further investigation is warranted for the disproportionate rise in incidence of metastatic breast, stomach, and kidney cancer among AYAs and their excess burden among AYA racial and ethnic minorities. The rising incidence of colorectal cancer among AYAs and middle-aged adults remains an additional concern.

In modern times, how important are breast cancer stage, grade and receptor subtype for survival: a population-based cohort study

Background

In breast cancer, immunohistochemistry (IHC) subtypes, together with grade and stage, are well-known independent predictors of breast cancer death. Given the immense changes in breast cancer treatment and survival over time, we used recent population-based data to test the combined influence of IHC subtypes, grade and stage on breast cancer death.

Methods

We identified 24,137 women with invasive breast cancer aged 20 to 74 between 2005 and 2015 in the database of the Cancer Registry of Norway. Kaplan-Meier curves, mortality rates and adjusted hazard ratios for breast cancer death were estimated by IHC subtypes, grade, tumour size and nodal status during 13 years of follow-up.

Results

Within all IHC subtypes, grade, tumour size and nodal status were independent predictors of breast cancer death. When combining all prognostic factors, the risk of death was 20- to 40-fold higher in the worst groups compared to the group with the smallest size, low grade and ER+PR+HER2− status. Among node-negative ER+HER2− tumours, larger size conferred a significantly increased breast cancer mortality. ER+PR−HER2− tumours of high grade and advanced stage showed particularly high breast cancer mortality similar to TNBC. When examining early versus late mortality, grade, size and nodal status explained most of the late (> 5 years) mortality among ER+ subtypes.

Conclusions

There is a wide range of risks of dying from breast cancer, also across small breast tumours of low/intermediate grade, and among node-negative tumours. Thus, even with modern breast cancer treatment, stage, grade and molecular subtype (reflected by IHC subtypes) matter for prognosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13058-021-01393-z.