Colon and rectal cancer: An emergent public health problem.

Colorectal cancer ranks third globally, with a high mortality rate. In the United States, and different countries in Europe, organized population screenings exist and include people between 50 and 74 years of age. These screenings have allowed an early diagnosis and consequently an improvement in health indicators. Colon and rectal cancer (CRC) is a disease of particular interest due to the high global burden associated with it and the role attributed to prevention and early diagnosis in reducing morbidity and mortality. This study is a review of CRC pathology and includes the most recent scientific evidence regarding this pathology, as well as a diagnosis of the epidemiological situation of CRC. Finally, the recommendation from a public health perspective will be discussed in detail taking into account the context and the most current recommendations.

[Watch and Wait for Rectal Cancer]. / Surveillance bei Watch-and-Wait nach neoadjuvanter Therapie beim Rektumkarzinom.

About one third of all colorectal carcinomas (CRC) are localised in the rectum. As part of a multimodal therapy concept, neoadjuvant therapy achieves downstaging of the tumour in 50-60% of cases and a so-called complete clinical response (cCR), defined as clinically (and radiologically) undetectable residual tumour after completion of neoadjuvant therapy, in 10-30% of cases.In view of the perioperative morbidity and mortality associated with radical rectal resection, including the occurrence of a symptom complex known as low anterior resection syndrome (LARS) and the need for deviation, at least temporarily, the question of the risk-benefit balance of organ resection in the presence of cCR has been raised. In this context, the therapeutic concept of a "watch-and-wait" approach with omission of immediate organ resection and inclusion in a structured surveillance regime, has emerged.For a safe, oncological implementation of this option, it is necessary to develop standards in the definition of a suitable patient clientele and the implementation of the concept. In addition to the initial correct selection of the patient group that is suitable for a primarily non-surgical procedure, the inherent goal is the early and sufficient detection of tumour recurrence (so-called local regrowth) during the "watch-and-wait" phase (surveillance).In this context, in this paper we address the questions of: 1. the optimal timing of initial re-staging, 2. the criteria for assessing the clinical response and selecting the appropriate patient clientele, 3. the rhythm and design of the surveillance protocol.

Survival of the Hmong population diagnosed with colon and rectal cancers in the United States.

BACKGROUND: The Hmong population constitutes an independent ethnic group historically dispersed throughout Southeast Asia; fallout from the Vietnam War led to their forced migration to the United States as refugees. This study seeks to investigate characteristics of the Hmong population diagnosed with in colorectal cancer (CRC) as well as survival within this population. METHODS: Cases of colon and rectal adenocarcinoma diagnosed between 2004 and 2017 were identified from the National Cancer Database (NCDB). Summary statistics of demographic, clinical, socioeconomic, and treatment variables were generated with emphasis on age and stage at the time of diagnosis. Cox-proportional hazard models were constructed for survival analysis. RESULTS: Of 881,243 total CRC cases within the NCDB, 120 were classified as Hmong. The average age of Hmong individuals at diagnosis was 58.9 years compared 68.7 years for Non-Hispanic White (NHW) individuals (p < 0.01). The distribution of analytic stage differed between the Hmong population and the reference NHW population, with 61.8% of Hmong individuals compared to 45.8% of NHW individuals with known stage being diagnosed at stage III or IV CRC compared to 0, I, or II (p = 0.001). However, there was no difference in OS when adjusting for potential confounders (HR 1.00 [0.77-1.33]; p = 0.998). CONCLUSIONS: Hmong individuals are nearly a decade younger at the time of diagnosis of CRC compared to the NHW individuals. However, these data do not suggest an association between Hmong ethnicity and overall survival, when compared to the NHW population.

Metabolic Signatures: Pioneering the Frontier of Rectal Cancer Diagnosis and Response to Neoadjuvant Treatment with Biomarkers-A Systematic Review.

Colorectal cancer (CRC) is one of the most aggressive, heterogenous, and fatal types of human cancer for which screening, and more effective therapeutic drugs are urgently needed. Early-stage detection and treatment greatly improve the 5-year survival rate. In the era of targeted therapies for all types of cancer, a complete metabolomic profile is mandatory before neoadjuvant therapy to assign the correct drugs and check the response to the treatment given. The aim of this study is to discover specific metabolic biomarkers or a sequence of metabolomic indicators that possess precise diagnostic capabilities in predicting the efficacy of neoadjuvant therapy. After searching the keywords, a total of 108 articles were identified during a timeframe of 10 years (2013-2023). Within this set, one article was excluded due to the use of non-English language. Six scientific papers were qualified for this investigation after eliminating all duplicates, publications not referring to the subject matter, open access restriction papers, and those not applicable to humans. Biomolecular analysis found a correlation between metabolomic analysis of colorectal cancer samples and poor progression-free survival rates. Biomarkers are instrumental in predicting a patient's response to specific treatments, guiding the selection of targeted therapies, and indicating resistance to certain drugs.

Neoadjuvant Short- Vs. Long-Course Radiation for Locally Advanced Rectal Cancer: How to Choose.

OPINION STATEMENT: Over the past decades, the treatment of locally advanced rectal cancer has evolved dramatically due to improvements in diagnostic imaging, surgical technique, and the addition of radiotherapy and/or chemotherapy. Fractionation of neoadjuvant radiotherapy with or without concurrent chemotherapy remains the subject of discussion and the question multiple recent trials have aimed to answer. In light of recent data and concern for locoregional recurrence, our institution favors long-course chemoradiation in most cases, especially in low-lying primaries, threatened circumferential resection margin, consideration of non-operative management, or if the surgeon has concerns for resectability. Exceptions would include cases of oligometastatic disease planned for metastasectomy in which curative-intent treatment was pursued or if additional factors required a reduction in treatment time.

p21 as a Predictor and Prognostic Indicator of Clinical Outcome in Rectal Cancer Patients.

The cell cycle plays a key and complex role in the development of human cancers. p21 is a potent cyclin-dependent kinase inhibitor (CDKI) involved in the promotion of cell cycle arrest and the regulation of cellular senescence. Altered p21 expression in rectal cancer cells may affect tumor cells' behavior and resistance to neoadjuvant and adjuvant therapy. Our study aimed to ascertain the relationship between the differential expression of p21 in rectal cancer and patient survival outcomes. Using tissue microarrays, 266 rectal cancer specimens were immunohistochemically stained for p21. The expression patterns were scored separately in cancer cells retrieved from the center and the periphery of the tumor; compared with clinicopathological data, tumor regression grade (TRG), disease-free, and overall survival. Negative p21 expression in tumor periphery cells was significantly associated with longer overall survival upon the univariate (p = 0.001) and multivariable analysis (p = 0.003, HR = 2.068). Negative p21 expression in tumor periphery cells was also associated with longer disease-free survival in the multivariable analysis (p = 0.040, HR = 1.769). Longer overall survival times also correlated with lower tumor grades (p= 0.011), the absence of vascular and perineural invasion (p = 0.001; p < 0.005), the absence of metastases (p < 0.005), and adjuvant treatment (p = 0.009). p21 expression is a potential predictive and prognostic biomarker for clinical outcomes in rectal cancer patients. Negative p21 expression in tumor periphery cells demonstrated significant association with longer overall survival and disease-free survival. Larger prospective studies are warranted to investigate the ability of p21 to identify rectal cancer patients who will benefit from neoadjuvant and adjuvant therapy.

Prognostic impact of tumor budding in rectal cancer after neoadjuvant therapy: a systematic review and meta-analysis.

BACKGROUND: Tumor budding (TB) is a negative prognostic factor in colorectal cancer; however, its prognostic impact following neoadjuvant therapy for patients with rectal cancer remains unclear. This study aims to assess the prognostic impact of TB and the correlation between TB and other pathological features in patients with rectal cancer after neoadjuvant therapy. METHODS: A comprehensive search of PubMed, Embase, Cochrane, Scopus, CNKI, Wanfang, and ClinicalKey databases was conducted for studies on the prognosis of TB in rectal cancer after neoadjuvant therapy from the inception of the databases to January 2023, and the final literature included was determined using predefined criteria. Quality assessment of the studies included, extraction of general and prognostic information from them, and meta-analyses were carried out progressively. RESULTS: A total of 11 studies were included, and the results of the meta-analysis showed that high-grade tumor budding (TB-1) increased the risk of poor 5-year disease-free survival (HR = 1.75, 95% CI 1.38-2.22, P < 0.00001), 5-year overall survival (HR = 1.77, 95% CI 1.21-2.59, P = 0.003), local recurrence (OR = 4.15, 95% CI 1.47-11.75, P = 0.007), and distant metastasis (OR = 5.36, 95% CI 2.51-11.44, P < 0.0001) in patients with rectal cancer after neoadjuvant therapy. TB-1 was significantly associated with poor differentiation and lymphatic, perineural, and venous invasion. CONCLUSION: Tumor budding is significantly correlated with unfavorable prognosis and poor pathological characteristics following neoadjuvant therapy for rectal cancer. We anticipate more high-quality, prospective studies in the future to confirm our findings. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42022377564.

[Anorectal melanoma : Update on clinical presentation, diagnosis and treatment]. / Anorektales malignes Melanom : Aktuelles zu Klinik, Diagnostik und Therapie.

Anorectal melanomas are a rare malignant type of cancer and pose a diagnostic challenge due to their hidden anatomical location. They are associated with nonspecific clinical symptoms and are therefore often misinterpreted as benign disease. The result is delayed diagnosis in the locally advanced or metastasized stage and an unfavorable prognosis. Given the overall low incidence of the tumor, no consensus guidelines for diagnosis or therapy are established either internationally or nationally at present. The present work intends to provide a comprehensive overview of the clinical aspects, diagnostics, and therapeutic approaches of anorectal melanoma based on the currently available literature.

Anastomotic Leakage in Relation to Type of Mesorectal Excision and Defunctioning Stoma Use in Anterior Resection for Rectal Cancer.

BACKGROUND: Anastomotic leakage after anterior resection for rectal cancer is more common after total mesorectal excision compared to partial mesorectal excision but might be mitigated by a defunctioning stoma. OBJECTIVE: The aim is to assess how anastomotic leakage is affected by type of mesorectal excision and defunctioning stoma use. DESIGN: This is a retrospective multicenter cohort study evaluating anastomotic leakage after anterior resection. Multivariable Cox regression with HRs and 95% CIs was used to contrast mesorectal excision types and defunctioning stoma use with respect to anastomotic leakage, with adjustment for confounding. SETTINGS: This multicenter study included patients from 11 Swedish hospitals between 2014 and 2018. PATIENTS: Patients who underwent anterior resection for rectal cancer were included. MAIN OUTCOMES MEASURES: Anastomotic leakage rates within and after 30 days of surgery are described up to 1 year after surgery. RESULTS: Anastomotic leakage occurred in 24.2% and 9.0% of 1126 patients operated with total and partial mesorectal excision, respectively. Partial compared to total mesorectal excision was associated with a reduction in leakage, with an adjusted HR of 0.46 (95% CI, 0.29-0.74). Early leak rates within 30 days were 14.9% with and 12.5% without a stoma, whereas late leak rates after 30 days were 7.5% with and 1.9% without a stoma. After adjustment, defunctioning stoma was associated with a lower early leak rate (HR 0.47; 95% CI, 0.28-0.77). However, the late leak rate was nonsignificantly higher in patients with defunctioning stomas (HR 1.69; 95% CI, 0.59-4.85). LIMITATIONS: This study was limited by its retrospective observational study design. CONCLUSIONS: Anastomotic leakage is common up to 1 year after anterior resection for rectal cancer, where partial mesorectal excision is associated with a lower leak rate. Defunctioning stomas seem to decrease the occurrence of leakage, although partially by only delaying the diagnosis. See Video Abstract . FUGA ANASTOMTICA SEGN EL TIPO DE EXCISIN MESORRECTAL Y LA CONFECCIN DE OSTOMA DE PROTECCIN EN LA RESECCIN ANTERIOR POR CNCER DE RECTO: ANTECEDENTES:La fuga anastomótica después de una resección anterior por cáncer de recto es más frecuente después de la excisión total del mesorrecto comparada con la excisión parcial del mismo, pero podría mitigarse con la confección de ostomías de protección.OBJETIVO:El objetivo es evaluar cómo la fuga anastomótica se ve afectada según el tipo de excisión mesorrectal y la confección de una ostomía de protección.DISEÑO:Estudio de cohortes multicéntrico y retrospectivo que evalúa la fuga anastomótica después de la resección anterior. Se aplicó la regresión multivariada de Cox con los índices de riesgo (HR) y los intervalos de confianza (IC) al 95% para contrastar los tipos de excisión mesorrectal y el uso de otomías de protección con respecto a la fuga anastomótica, realizando ajustes respecto a las variables de confusión.AJUSTES:El presente estudio multicéntrico incluyó pacientes de 11 hospitales suecos entre 2014 y 2018.PACIENTES:Se incluyeron todos aquellos sometidos a resección anterior por cáncer de recto.PRINCIPALES MEDIDAS DE RESULTADOS:Las tasas de fuga anastomótica dentro y después de los 30 días de la cirugía fueron descritos hasta un año mas tarde al acto quirúrgico.RESULTADOS:La fuga anastomótica ocurrió en el 24,2% y el 9,0% de 1126 pacientes operados por excisión total y parcial del mesorrecto respectivamente.La excisión parcial del mesorrecto en comparación con la total se asoció con una reducción de la fuga, HR ajustado de 0,46 (IC del 95 %: 0,29 a 0,74). Las tasas de fuga temprana dentro de los 30 días fueron del 14,9 % con y el 12,5 % sin estoma, mientras que las tasas de fuga tardía después de 30 días fueron del 7,5 % con y el 1,9 % sin estoma.Después del ajuste de variables de confusión, las ostomías de protección se asociaron con una tasa de fuga temprana más baja (HR 0,47; IC 95 %: 0,28-0,77). Sin embargo, la tasa de fuga tardía no fue significativamente mayor en pacientes ostomizados (HR 1,69; IC 95%: 0,59-4,85).LIMITACIONES:Las limitaciones del presente estudio estuvieron vinculadas con el diseño de tipo observacional y retrospectivo.CONCLUSIONES:La fuga anastomótica es común hasta un año después de la resección anterior por cáncer de recto, donde la excisión parcial del mesorrecto se asocia con una menor tasa de fuga. La confección de ostomías de protección parece disminuir la aparición de fuga anastomótica, aunque en parte sólo retrasen el diagnóstico. (Traducción-Dr. Xavier Delgadillo ).

Pathological-Features-Modified TNM Staging System Improves Prognostic Accuracy for Rectal Cancer.

BACKGROUND: Variations in survival outcomes are observed in the eighth edition of the American Joint Committee on Cancer TNM staging system. OBJECTIVE: Machine learning ensemble methods were used to develop and evaluate the effectiveness of a pathological-features-modified TNM staging system in predicting survival for patients with rectal cancer by use of commonly reported pathological features, such as histological grade, tumor deposits, and perineural invasion, to improve the prognostic accuracy. DESIGN: This was a retrospective population-based study. SETTINGS: Data were assessed from the database of the Surveillance, Epidemiology, and End Results Program. PATIENTS: The study cohort comprised 14,468 patients with rectal cancer diagnosed between 2010 and 2015. The development cohort included those who underwent surgery as the primary treatment, whereas patients who received neoadjuvant therapy were assigned to the validation cohort. MAIN OUTCOME MEASURES: The primary outcome measures included cumulative rectal cancer survival, adjusted HRs, and both calibration and discrimination statistics to evaluate model performance and internal validation. RESULTS: Multivariable Cox regression analysis identified all 3 pathological features as prognostic factors, after which patients were categorized into 4 pathological groups based on the number of pathological features (ie, 0, 1, 2, and 3). Distinct survival differences were observed among the groups, especially with patients with stage III rectal cancer. The proposed pathological-features-modified TNM staging outperformed the TNM staging in both the development and validation cohorts. LIMITATIONS: Retrospective in design and lack of external validation. CONCLUSIONS: The proposed pathological-features-modified TNM staging could complement the current TNM staging by improving the accuracy of survival estimation of patients with rectal cancer. See Video Abstract . EL SISTEMA DE ESTADIFICACIN TNM CON CARACTERSTICAS PATOLGICAS MODIFICADO MEJORA LA PRECISIN DEL PRONSTICO DEL CNCER DE RECTO: ANTECEDENTES:Se observan variaciones en los resultados de supervivencia en el sistema de estadificación TNM del Comité Conjunto Americano del Cáncer 8º ediciónOBJETIVO:Se utilizaron métodos conjuntos de aprendizaje automático para desarrollar y evaluar la eficacia de un sistema de estadificación con características patológicas modificadas de tumores, ganglios y metástasis para predecir la supervivencia de pacientes con cáncer de recto, utilizando algunas características patológicas comúnmente informadas, como el grado histológico, depósitos tumorales e invasión perineural, para mejorar la precisión del pronóstico.DISEÑO:Este fue un estudio retrospectivo de base poblacional.ENTERNO CLINICO:Se recuperaron y evaluaron datos de la base de datos de Vigilancia, Epidemiología y Resultados Finales.PACIENTES:La cohorte del estudio estuvo compuesta por 14,468 pacientes con cáncer de recto diagnosticados entre 2010 y 2015. La cohorte de desarrollo incluyó a aquellos que se sometieron a cirugía como tratamiento primario, mientras que los pacientes que recibieron terapia neoadyuvante fueron asignados a la cohorte de validación.PRINCIPALES MEDIDAS DE RESULTADO:Las medidas de resultado primarias incluyeron supervivencia acumulada del cáncer de recto, índices de riesgo ajustados y estadísticas de calibración y discriminación para evaluar el rendimiento del modelo y la validación interna.RESULTADOS:El análisis de regresión multivariable de Cox identificó las tres características patológicas como factores pronósticos, después de lo cual los pacientes se clasificaron en cuatro grupos patológicos según el número de características patológicas (es decir, 0, 1, 2 y 3). Se observaron distintas diferencias en la supervivencia entre los grupos, especialmente en los pacientes en estadio III. La estadificación propuesta con características patológicas modificadas de tumores-ganglios-metástasis superó a la estadificación TNM tanto en las cohortes de desarrollo como en las de validación.LIMITACIONES:Diseño retrospectivo y falta de validación externa.CONCLUSIONES:La estadificación propuesta con características patológicas modificadas de tumores-ganglios-metástasis podría complementar la estadificación TNM actual al mejorar la precisión de la estimación de supervivencia de los pacientes con cáncer de recto. (Traducción- Dr. Francisco M. Abarca-Rendon ).

Temporal trends in age- and stage-specific incidence of colorectal adenocarcinomas in Germany.

BACKGROUND: A national colorectal cancer (CRC) screening programme was launched in 2002 in Germany. A comprehensive evaluation of the programme effectiveness using real-world data is still lacking. In addition, there are regional reports on increasing colorectal cancer incidence in younger populations. Therefore, we aimed to describe and compare the overall, age- and stage-specific incidence trends for colorectal, colon and rectal cancer. METHODS: We used data from seven population-based cancer registries in Germany. We report absolute and relative changes in incidence rates between the early screening phase (2003-2005) and the most recent time period available (2015-2017), as well as annual percent changes. We analysed incidences according to tumour site (colorectum, colon, and rectum) and to six age groups (young adults: 15-34, 35-39, 40-49, screening-entitled/older adults: 50-54, 55-69 and 70 + years old). RESULTS: In our sample of 271,011 colorectal adenocarcinomas, about two-thirds were located in the colon and 95% of them occurred in the age group 50+ (50-54: 5%, 55-69: 32.8%, 70+: 57.2%). For the time period 2003-2005 the age-specific incidence rates of individuals in the age group 55-69 were about 76/100,00 for colon and 54/100,000 for rectal cancer (age group 70 + colon: 179/100,000; rectum: 84/100,000). The incidence rates in young adults were less than 13% of that of individuals in the age group 55-69 (< 5% of individuals aged 70+; <33% of individuals aged 50-54). Over time, incidence decreased in individuals at the age of 55+, for all subsites considered as well as for early and late stage cancers (with few exceptions), while incidence of young adult CRC (both early and late stage) increased steepest in the youngest age groups. For late stage rectal cancer, a shift was observed in all age groups from UICC stage IV to stage III being the most frequent stage. CONCLUSIONS: Six years after the introduction of the national colonoscopy screening program, late stage CRC incidence began to decline substantially in the screening-eligible age groups (55-69, 70+). It is likely that this decline and the increase in early stage CRC observed in younger age groups can be attributed to the program. Long lasting public awareness campaigns for CRC screening might have led to opportunistic screening in younger adults. Whether these benefits outweigh the possible harm of screening in younger age groups remains unclear.

Transanal minimally invasive surgery for benign and malignant rectal lesions: midterm outcomes from a tertiary center.

BACKGROUND: Although transanal minimally invasive surgery (TAMIS) for rectal neoplasia has gained wide acceptance, the mid-term and long-term outcomes are not widely reported in the literature. OBJECTIVE: Describe the mid-term outcomes of patients who underwent TAMIS for benign and malignant rectal lesions in a single center. DESIGN: Retrospective cohort study. SETTINGS: Tertiary referral center. PATIENTS AND METHODS: Demographic, clinical, and oncological outcomes of patients who underwent TAMIS between January 2015 and December 2022 were prospectively collected. The indication for TAMIS was based on the National Comprehensive Cancer Network guidelines. The follow up for the cancer patients included clinical examination, tumor markers every 6 months and MRI rectum at the end of one year. In addition, colonoscopy and CT scan at years one and three and a final CT scan and colonoscopy at year five. MAIN OUTCOME MEASURES: Mid-term oncological and clinical outcome. RESULTS: Thirty elective TAMIS procedures included adenocarcinoma for 33.3% (n=10) of the patients, 20% (n=6) neuroendocrine tumor and the 40% (n=12) were adenomatous lesions. Negative resection margins were achieved in all malignant lesions. Perioperative complications occurred in 2 patients (6.6%), one patient had breaching into the peritoneal cavity, and postoperative hypotension occurred in another patient. The median follow-up time was 23 months (range: 5-72 months). Two patients with adenoma and positive margins developed recurrent adenoma (6.6%) and one patient with initial polypectomy biopsy of adenocarcinoma, had TAMIS with histopathology of adenoma and distant metastasis had developed. CONCLUSIONS: TAMIS for local excision of rectal neoplasia is a valid option with favorable mid-term outcomes provided there is adherence to careful selection criteria. LIMITATIONS: Retrospective nature and small number of the patients.

Post-colonoscopy rectal cancer in Swedish patients with Crohn's disease 2001-2015: a population-based case review study.

OBJECTIVE: Post-colonoscopy colorectal cancer (PCCRC) is a key quality indicator of colonoscopy, and PCCRC rates are high in the IBD population. Rectal cancer, an important risk factor for PCCRC among patients with Crohn's disease (CD), has not previously been examined. METHODS: Swedish adult patients with CD who underwent a colonoscopy within 36 months before a rectal cancer diagnosis between 2001 and 2015 were identified through the National Patient and Cancer registers. Their medical records were reviewed and a root-cause analysis and a sub-categorization according to the World Endoscopic Organization (WEO) were performed. RESULTS: Of 24 patients with CD and PCCRC in the rectum, 79% were men and the median age was 50 (IQR 45-59) years. The median disease duration was 21.5 (IQR 19-30) years. The cancer was located in the distal 5 cm of the rectum in 63% of the cases. Retroversion in the rectum was reported in only one case. The most common plausible explanation for PCCRC was 'possible missed lesion, prior examination adequate' (63%); when adding retroversion in the rectum, instead 77% of examinations were considered negative but deemed as inadequate. The most common PCCRC sub-category was non-interval type C (54%) and B (37%). Among those with type C, 38% should have been included in surveillance according to present guidelines. CONCLUSION: Better adherence to surveillance guidelines and more meticulous follow-up is warranted. The importance of performing rectal palpation and retroversion in the rectum is underscored and we suggest that this is included in the WEO algorithm.

Rectal Adenocarcinoma Presenting as a Cervical Mass: A Case Report.

BACKGROUND Invasive cervical tumors are often seen in clinical practice. However, there are multiple structures within the pelvis, and invasion of the cervix from another site must be included in the differential diagnosis. In such cases, a multidisciplinary approach is needed to define the organ of tumor origin. Ensuring proper staging and histologic analysis are critical for optimal management. CASE REPORT We present a case of a 68-year-old woman who presented to her gynecologist with painless post-menopausal vaginal bleeding. She was diagnosed with a locally aggressive cervical adenocarcinoma, which was histologically confirmed by an in-office biopsy. She was referred to the gynecologic oncology service at a tertiary care hospital for definitive management, where a thorough clinical workup was performed. Physical exam revealed that the mass had invaded the anterior rectal wall. Through a multidisciplinary approach and a repeat biopsy, she was correctly diagnosed with an invasive rectal adenocarcinoma. She was treated with neoadjuvant chemoradiotherapy and underwent curative surgery. Had she been incorrectly treated as having a primary cervical adenocarcinoma, there would have been no role for surgery. The change in the organ of primary drastically altered the patient's management and outcome. She is currently undergoing surveillance with cross-sectional imaging. CONCLUSIONS Cervical masses originating from non-gynecologic organs can be difficult to differentiate on physical exam and histologic analysis. When a mass involves the rectum, an invasive primary rectal adenocarcinoma must be included in the differential. This will have a significant impact on patient management and ultimately on patient survival.

Wavelet scattering networks in deep learning for discovering protein markers in a cohort of Swedish rectal cancer patients.

BACKGROUND: Cancer biomarkers play a pivotal role in the diagnosis, prognosis, and treatment response prediction of the disease. In this study, we analyzed the expression levels of RhoB and DNp73 proteins in rectal cancer, as captured in immunohistochemical images, to predict the 5-year survival time of two patient groups: one with preoperative radiotherapy and one without. METHODS: The utilization of deep convolutional neural networks in medical research, particularly in clinical cancer studies, has been gaining substantial attention. This success primarily stems from their ability to extract intricate image features that prove invaluable in machine learning. Another innovative method for extracting features at multiple levels is the wavelet-scattering network. Our study combines the strengths of these two convolution-based approaches to robustly extract image features related to protein expression. RESULTS: The efficacy of our approach was evaluated across various tissue types, including tumor, biopsy, metastasis, and adjacent normal tissue. Statistical assessments demonstrated exceptional performance across a range of metrics, including prediction accuracy, classification accuracy, precision, and the area under the receiver operating characteristic curve. CONCLUSION: These results underscore the potential of dual convolutional learning to assist clinical researchers in the timely validation and discovery of cancer biomarkers.

Rectal cancer presentation during the COVID-19 pandemic: Are decreasing screening rates leading to an increase in acute presentations?

Nearly 23 million adults ages 50-75 are overdue for colorectal cancer (CRC) screening. In March 2020, the Centers for Medicare & Medicaid issued guidance that all non-urgent procedures be delayed due to the COVID-19 pandemic. Screening delays may have effects on the presentation of rectal cancer and the natural history of the disease. The aim of this study was to determine if procedural suspension due to the COVID-19 pandemic was associated with an increased proportion of acute presentations or more advanced stage at diagnosis for patients with rectal cancer. We conducted a single-center, retrospective review of adult patients with new or recurrent rectal adenocarcinoma from 2016-2021. We compared patients presenting before (pre-COVID) to those diagnosed after (COVID) March 1, 2020. Of 208 patients diagnosed with rectal cancer, 163 were diagnosed pre-COVID and 45 patients in the COVID group. Cohorts did not differ among age, sex, race, insurance status, marital status, rurality, or BMI. There was no difference in stage at presentation with the majority diagnosed with stage III disease (40.0% vs 33.3%, p = 0.26). Similar proportions of patients presented acutely (67.5% vs 64.4%, p = 0.71). Presenting symptoms were also similar between cohorts. On adjusted analysis, male sex, white race, and uninsured status were found to have significant impact acuity of presentation, while diagnosis before or after the onset of the pandemic remained non-significant (OR 1.25, 95% CI0.57-2.72; p = 0.59). While screening rates have decreased during the COVID pandemic, patients with rectal cancer did not appear to have an increased level of acuity or stage at presentation. These findings could result from the indolent nature of the disease and may change as the pandemic progresses.