Over-diagnosis in breast cancer screening

Biological correlates before esophageal cancer screening and after diagnosis

Almost 50% of the world's esophageal cancer (EC) cases occur in China, and the impact of cancer screening has long been a controversial topic. The study was designed to evaluate the biological correlates of EC screening and subsequent diagnosis in China. Based on the national cohort of esophageal cancer program, a prospective multicenter study in high-risk regions was conducted from 2017 to 2019. 61 participants received twice esophageal endoscopy screening and pathological biopsy successively (with a mean follow-up of 14.03 months). Box-Cox-power transformation and two-way repeated measures ANOVA were used to evaluate hormone cortisol and immunoglobulin (IgA, IgG, IgM) levels in plasma, reflecting their stress, immune function, and biological correlates before screening and after knowing the diagnosis. The median of cortisol, IgA, IgG, and IgM in pre-screening was 15.46 ug/dL, 1.86 g/L, 12.14 g/L, and 0.91 g/L, corresponding value at post-diagnosis was 15.30 ug/dL, 2.00 g/L, 12.79 g/L, and 0.94 g/L, respectively. No significant differences in biological indicators were found between normal and esophagitis and low-grade intraepithelial neoplasia before screening and after diagnosis. After normality transformation, cortisol, IgA, IgG and IgM levels were (0.25 ± 0.04) U/mL, (0.72 ± 0.13) (g/L), (2.44 ± 0.22) (g/L) and (0.98 ± 0.25) (g/L) before screening, (0.25 ± 0.05) U/mL, (0.70 ± 0.13) (g/L), (2.48 ± 0.21) (g/L) and (1.00 ± 0.25) (g/L) after diagnosis, respectively. Repeated Measures ANOVA showed that the main effects were significant on IgA levels between pre-screening and post-diagnosis (P = 0.019). No interaction effects on biological levels between pre-post screening and esophageal pathology, anxiety states (all P > 0.05). Little biological correlates were found both before screening and after diagnosis. Cortisol and IgA dropped less significantly, while IgM and IgA were increased slightly after diagnosis. Further multi-round longitudinal studies are needed to validate these results.

Impact of adjuvant chemotherapy on the survival of patients with breast cancer diagnosed by screening

The aim of this study is to determine the survival of patients with breast cancer treated with adjuvant chemotherapy (ACh) after the diagnosis by screening, taking comorbidity into account. This multicenter cohort study examined a population of patients taking part in four national screening programs for the early detection of breast cancer (localized or locally advanced), during the period 2000‐2008. Of the 1248 cancers detected, 266 were prevalent (21.3%), 633 were incident (50.7%), and 349 were interval (27.9%). No significant differences were detected between the three groups in terms of the distribution of comorbidity according to the CCI. After a median follow‐up of 102 months, 22.1% of the patients with interval cancer had died. The corresponding figures for the incident and prevalent cancers were 10.4% and 7.9%, respectively (P < .001). The adjusted Cox regression analysis by the stage, CCI and group revealed no differences in the risk of recurrence between the different groups according to the ACh performed. However, there were significant differences in the overall survival; for the interval cancer group without ACh, the risk of death was higher (Hazard ratio: 2.5 [1.0‐6.2]) than for the other two groups. However, for the prevalent and incident groups that did not receive ACh, there was no greater risk of death. This study shows that adjuvant chemotherapy seems to benefit patients with interval breast cancer, who have a poorer prognosis than those with prevalent or incident cancer. However, the role of ACh is unclear with respect to prevalent and incident cancers when comorbidity is taken into account.

Detection methods predict differences in biology and survival in breast cancer patients

BACKGROUND

The aim of this study was to measure the biological characteristics involved in tumorigenesis and the progression of breast cancer in symptomatic and screen-detected carcinomas to identify possible differences.

METHODS

For this purpose, we evaluated clinical-pathological parameters and proliferative and apoptotic activities in a series of 130 symptomatic and 161 screen-detected tumors.

RESULTS

After adjustment for the smaller size of the screen-detected carcinomas compared with symptomatic cancers, those detected in the screening program presented longer disease-free survival (RR = 0.43, CI = 0.19-0.96) and had high estrogen and progesterone receptor concentrations more often than did symptomatic cancers (OR = 3.38, CI = 1.72-6.63 and OR = 3.44, CI = 1.94-6.10, respectively). Furthermore, the expression of bcl-2, a marker of good prognosis in breast cancer, was higher and HER2/neu expression was lower in screen-detected cancers than in symptomatic cancers (OR = 1.77, CI = 1.01-3.23 and OR = 0.64, CI = 0.40-0.98, respectively). However, when comparing prevalent vs incident screen-detected carcinomas, prevalent tumors were larger (OR = 2.84, CI = 1.05-7.69), were less likely to be HER2/neu positive (OR = 0.22, CI = 0.08-0.61) and presented lower Ki67 expression (OR = 0.36, CI = 0.17-0.77). In addition, incident tumors presented a shorter survival time than did prevalent ones (RR = 4.88, CI = 1.12-21.19).

CONCLUSIONS

Incident carcinomas include a variety of screen-detected carcinomas that exhibit differences in biology and prognosis relative to prevalent carcinomas. The detection method is important and should be taken into account when making therapy decisions.

Informed choice and breast cancer screening

It is an accepted principle of clinical practice that any intervention should be preceded by informed consent demonstrating that the individual understands both the potential benefits and harms of that intervention. I believe that this principle has been neglected when women are invited for mammographic screening. Public health agencies promote screening as an unequivocal 'good' by publicizing the benefit in mortality reduction in relative terms and avoiding discussion of potential harms. Each woman is encouraged to believe that, whatever the outcome of her individual screening experience, she has in some way benefited. I believe that the harm:benefit margins for screening are finely balanced and that the individual woman should be able to make an informed choice based on the balance of benefit versus harm for an individual, rather than for the total population of women in the screening age group.

Competing causes of death for women with breast cancer and change over time from 1975 to 2003

This study was to determine whether the proportion of death due to breast cancer changed over time in different cohorts of women diagnosed with breast cancer. We identified 316,149 women with breast cancer at age 20 or older during 1975-2003 from the Surveillance, Epidemiology, and End Results 9 tumor registries in the United States. Logistic regression models were used to assess the effects of time period on the likelihood of dying because of breast cancer as underlying cause of death, adjusting for other factors. Overall, underlying cause of death was 52.8% due to breast cancer, 17.8% due to heart disease, and 4.9% due to stroke. Percentage of death due to breast cancer did not change significantly from 1975 to 2003 in those who died < 12 months after diagnosis, but decreased significantly in women who died between 1 and 15 years. Risk of death due to breast cancer in women diagnosed during 1995-1998 was significantly lower than those in 1975-1979 (odds ratio = 0.79, 95% confidence interval = 0.70-0.89), after adjusting for age, race, ethnicity, and tumor stage. Percentage of death due to breast cancer decreased significantly with age from 87.5% in women < 40% to 30.7% in those 80 or older, which was not significantly affected by year of diagnosis. Proportion of death due to breast cancer increased with advanced tumor stage and was similar in various racial/ethnic groups of population. The findings demonstrated that the impact of breast cancer on overall death was reduced after 1 year of diagnosis, but suggested the need for continued cancer surveillance.

A comparative study of risk factors and prognostic features between symptomatic and screen detected breast cancer

AIMS

To compare prognostic factors in screen detected breast cancer (SDBC) and symptomatically presenting breast cancer (SBC).

METHODS

Data were examined on 100 SDBC and 100 SBC. Multiple clinical patient factors were assessed including histopathological features. Using the Gail model each patient's risk of developing breast cancer was calculated and these data were examined for differences between groups.

RESULTS

There was no difference in the mean age of patient presentation or in the risk of breast cancer development between groups (2.2% vs. 2.2%, SDBC vs. SBC, actuarial risk of cancer at 5 years). SDBC patients had a significantly lower grade (1.95 vs. 2.44, SDBC vs. SBC, P<0.05), a smaller size of tumour (15.4mm vs. 29.3mm, SDBC vs. SBC, P<0.05) and a higher rate of oestrogen (94% vs. 81%, P<0.05) and progesterone (75% vs. 52%, P<0.05) receptor positivity. When compared using the Nottingham Prognostic Index, SDBC was associated with a better prognosis (r=-0.444, P<0.001).

CONCLUSIONS

Though both groups have similar demographics and risk, SDBC patients appear to have more favourable prognostic features. This has implications for the application of systemic therapy in breast cancer and supports the observation that SDBC is a more indolent form of disease.