How asymptomatic are early cancer patients of five organs based on registry data in Japan

Stage at diagnosis of colorectal cancer through diagnostic route: Who should be screened?

BACKGROUND

Colorectal cancer (CRC) is a global health concern, with advanced-stage diagnoses contributing to poor prognoses. The efficacy of CRC screening has been well-established; nevertheless, a significant proportion of patients remain unscreened, with > 70% of cases diagnosed outside screening. Although identifying specific subgroups for whom CRC screening should be particularly recommended is crucial owing to limited resources, the association between the diagnostic routes and identification of these subgroups has been less appreciated. In the Japanese cancer registry, the diagnostic routes for groups discovered outside of screening are primarily categorized into those with comorbidities found during hospital visits and those with CRC-related symptoms.

AIM

To clarify the stage at CRC diagnosis based on diagnostic routes.

METHODS

We conducted a retrospective observational study using a cancer registry of patients with CRC between January 2016 and December 2019 at two hospitals. The diagnostic routes were primarily classified into three groups: Cancer screening, follow-up, and symptomatic. The early-stage was defined as Stages 0 or I. Multivariate and univariate logistic regressions were exploited to determine the odds of early-stage diagnosis in the symptomatic and cancer screening groups, referencing the follow-up group. The adjusted covariates were age, sex, and tumor location.

RESULTS

Of the 2083 patients, 715 (34.4%), 1064 (51.1%), and 304 (14.6%) belonged to the follow-up, symptomatic, and cancer screening groups, respectively. Among the 2083 patients, CRCs diagnosed at an early stage were 57.3% (410 of 715), 23.9% (254 of 1064), and 59.5% (181 of 304) in the follow-up, symptomatic, and cancer screening groups, respectively. The symptomatic group exhibited a lower likelihood of early-stage diagnosis than the follow-up group [P < 0.001, adjusted odds ratio (aOR), 0.23; 95% confidence interval (95%CI): 0.19-0.29]. The likelihood of diagnosis at an early stage was similar between the follow-up and cancer screening groups (P = 0.493, aOR for early-stage diagnosis in the cancer screening group vs follow-up group = 1.11; 95%CI = 0.82-1.49).

CONCLUSION

CRCs detected during hospital visits for comorbidities were diagnosed earlier, similar to cancer screening. CRC screening should be recommended, particularly for patients without periodical hospital visits for comorbidities.

Computational modeling of locoregional recurrence with spatial structure identifies tissue-specific carcinogenic profiles

Introduction

Local and regional recurrence after surgical intervention is a significant problem in cancer management. The multistage theory of carcinogenesis precisely places the presence of histologically normal but mutated premalignant lesions surrounding the tumor - field cancerization, as a significant cause of cancer recurrence. The relationship between tissue dynamics, cancer initiation and cancer recurrence in multistage carcinogenesis is not well known.

Methods

This study constructs a computational model for cancer initiation and recurrence by combining the Moran and branching processes in which cells requires 3 or more mutations to become malignant. In addition, a spatial structure-setting is included in the model to account for positional relativity in cell turnover towards malignant transformation. The model consists of a population of normal cells with no mutation; several populations of premalignant cells with varying number of mutations and a population of malignant cells. The model computes a stage of cancer detection and surgery to eliminate malignant cells but spares premalignant cells and then estimates the time for malignant cells to re-emerge.

Results

We report the cellular conditions that give rise to different patterns of cancer initiation and the conditions favoring a shorter cancer recurrence by analyzing premalignant cell types at the time of surgery. In addition, the model is fitted to disease-free clinical data of 8,957 patients in 27 different cancer types; From this fitting, we estimate the turnover rate per month, relative fitness of premalignant cells, growth rate and death rate of cancer cells in each cancer type.

Discussion

Our study provides insights into how to identify patients who are likely to have a shorter recurrence and where to target the therapeutic intervention.

Impact of coronavirus disease 2019 on the number of newly diagnosed cancer patients and examinations and surgeries performed for cancer in Japan: a nationwide study

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic has rapidly and dramatically influenced healthcare across Japan. However, the influence of the COVID-19 pandemic on the number of newly diagnosed cancer, surgical treatment, and diagnostic examination for cancer types have not been completely investigated all over Japan. This study aimed to analyze the number of cases before and during the COVID-19 pandemic.

METHODS

This retrospective study was a survey that asked to provide the number of cases diagnosed with gastric, colorectal, lung, breast, and cervical cancer between January 2019 and December 2020. The survey was sent to tertiary healthcare hospitals, including national cancer institutions, university hospitals, and general hospitals, all over Japan. Data obtained from 105 of 486 surveyed hospitals were evaluated, and the number of cases in each quarter in 2020 was compared with that in the equivalent quarter in 2019.

RESULTS

In the second quarter (Q2), significant reductions were observed in the median number of newly diagnosed cases from 2019 to 2020: gastric cancer, 26.7% (43 vs. 32, p <  0.001); colorectal cancer, 17.9% (52 vs. 40, p <  0.001); lung cancer, 12.3% (53.5 vs. 47, p <  0.001); and breast cancer, 13.1% (43 vs. 35.5, p <  0.001). A significant reduction of 11.4% (9 vs. 8, p = 0.03) was observed in the third quarter (Q3) for cervical cancer. In Q2, the number of cases decreased by 30.9% (25 vs. 15, p <  0.001) for stage I gastric cancer, by 27.3% (12 vs. 9, p <  0.001) for stage I colorectal cancer, and by 17.6% (13 vs. 10, p <  0.001) for stage II breast cancer. The magnitude of reduction was significant for the localized stages of gastric, colorectal, and breast cancer according to diagnostic examinations in Q2 and surgical and endoscopic treatment in Q3 rather than that for lung or cervical cancer.

CONCLUSIONS

COVID-19 has prolonged collateral effects on cancer care, including examination, diagnosis, and surgery, with significant effects on gastric cancer, followed by colorectal, lung, breast, and cervical cancer in Japan.

Lesiones premalignas y malignas del estómago en pacientes sin tamización para cáncer gástrico

Introducción. Para establecer una frecuencia de seguimiento como método de tamización en cáncer gástrico, se propone la endoscopia en pacientes mayores de 35 años con síntomas de dispepsia, y en pacientes mayores de 40 años con alto riesgo. La demora en la realización de la primera endoscopia en la vida de un paciente incrementa el riesgo de no detectar lesiones premalignas ni cáncer potencialmente prevenible. Los objetivos de nuestro estudio fueron describir el número de pacientes mayores de 40 años con endoscopia de primera vez y evaluar la presencia de lesiones premalignas y malignas del estómago en pacientes sin tamización. Métodos. Revisión retrospectiva de base de datos. Se describieron hallazgos de informes de histopatología en pacientes mayores de 40 años (lesiones premalignas y malignas). Adicionalmente se describieron las variables sociodemográficas de los pacientes con endoscopia de primera vez y la presencia de infección por Helicobacter pylori en la población mencionada. Resultados. Setenta y ocho pacientes (23,6 %) tuvieron una endoscopia de primera vez siendo mayores de 40 años. En el 44 % de los pacientes se encontró la presencia de Helicobacter pylori, 25,4 % de los pacientes presentaron atrofia gástrica, 23,1 % metaplasia, ningún paciente presentó displasia y un paciente (1,3 %) presentó un adenocarcinoma gástrico. Discusión. Los resultados de nuestro estudio muestran un número elevado de pacientes sin endoscopia de tamización. Nuestro estudio resalta la importancia del uso de la endoscopia de tamización en la prevención, así como en el diagnóstico temprano de cáncer gástrico y sugiere mayor adherencia a las guías de práctica clínica.