Lower Gastrointestinal Cancer Research Articles

Management of MSI-H/dMMR Upper and Lower Gastrointestinal Cancers

Management of MSI-H/dMMR Upper and Lower Gastrointestinal Cancers

Direct oral anticoagulant-associated bleeding complications in patients with gastrointestinal cancer and venous thromboembolism

BackgroundDirect oral anticoagulants (DOACs) have become widely used for cancer-associated venous thromboembolism (VTE). However, DOAC-associated bleeding complications remain challenging, especially in patients with gastrointestinal (GI) cancer. This study aimed to compare the bleeding outcomes between patients with upper or lower GI cancers and those without GI cancer. MethodsUsing the COMMAND VTE Registry-2 database, which is a multicenter registry enrolling 5197 consecutive acute symptomatic VTE patients among 31 centers in Japan between January 2015 and August 2020, we identified 1149 active cancer patients with DOACs (upper GI cancer: N = 88; lower GI cancer: N = 114; non-GI cancer: N = 947). The primary outcome was major bleeding during anticoagulation therapy, which was evaluated in the competing risk regression model. ResultsThe upper GI cancer group had a lower mean body weight, and most often had anemia. The cumulative 5-year incidence of major bleeding was higher in the upper GI cancer group (upper GI cancer: 22.4 %, lower GI cancer: 15.4 %, and non-GI cancer: 11.6 %, P = 0.015). The most frequent major bleeding site in the upper GI cancer group was the upper GI (53 %), followed by the lower GI (24 %). After adjusting for the confounders, the excess risk in upper GI cancer relative to non-GI cancer remained significant for major bleeding (adjusted subhazard ratio, 2.25; 95 %CI, 1.31–3.87, P = 0.003), but that in lower GI cancer was insignificant. ConclusionsUpper GI cancer, but not lower GI cancer, as compared to non-GI cancer was associated with a higher risk for major bleeding during anticoagulation therapy with DOACs.Clinical Trial Registration: URL: http://www.umin.ac.jp/ctr/index.htmUnique identifier: UMIN000044816.

Anaerobic gram-negative rod bacteremia as a marker of gastrointestinal cancer in Japanese patients: a single-center retrospective study.

Gram-negative rod (GNR) bacteremia has been suggested as a clinical marker of occult cancer; however, no studies are available in this regard in the Japanese population. Here, we investigated the risk factors for gastrointestinal cancer with GNR bacteremia. Patients with GNR bacteremia admitted to St. Luke's International Hospital between January 2011 and July 2021 were included. The clinical data of patients with and without cancer, 1 year before and after GNR bacteremia diagnosis, were compared. Univariate analysis was performed using χ2 and Fisher's exact tests for categorical variables and the Mann-Whitney U test for continuous variables, while multivariable analysis was performed using logistic regression analysis, and a P of <0.05 was considered statistically significant. Of 2,296 GNR bacteremia-positive patients, 96 were associated with gastrointestinal cancer, and univariate analysis showed significant differences between the gastrointestinal cancer and comparison groups in terms of mean body mass index (BMI; 20.5 vs. 21.8 kg/m2), Enterobacterales detection (64.6% vs. 81.3%), and anaerobic GNR detection (24.0% vs. 8.5%). Thirty-five (36%) and 61 (64%) patients had upper and lower gastrointestinal cancer, respectively. There were 23 patients with anaerobic GNR bacteremia related to 24 strains (upper and lower gastrointestinal cancer, 5 and 18 cases, respectively). Multivariate analysis identified anaerobic GNR [odds ratio, 3.440; 95% confidence interval (CI): 2.085-5.675, P<0.001] as a significant risk factor for cancer. Anaerobic GNR in blood cultures may be a risk factor for gastrointestinal cancer. Therefore, it is necessary consider cancer workup, such as endoscopy, for patients with anaerobic GNR bacteremia.

Clinical and economic burden of surgical complications during hospitalization for digestive cancer surgery in France.

Surgical complications and particularly infections after digestive cancer surgery remain a major health and economic problem and its burden in France is not well documented. The aim of this study was to analyse recent data regarding surgical complications in patients undergoing major digestive cancer surgery, and to estimate its burden for the French society. Using the 2018 French hospital discharge database and 2017 National CostStudy we studied hospital stays for surgical resection in patients withdigestive cancer. The population was divided into three groups based onpostoperative outcomes: no complications (NC), related infectious complications (RIC) and other complications. The main analysis compared the length and cost per stay between RIC and NC. Forty-Four thousand one hundred and twenty-three stays following a digestive cancer resection were identified. Lower gastro-intestinal cancers were the most prevalent representing 74.8% of stays, the rate of malnutrition was 32.8% and 15.8% of patients presented RIC. Mean (SD) length of stay varied from 11,7 (9.0) days for NC to 25,5 days (19.5) for RIC (p < 0.01). The mean cost per patients' stay (SD) varied from €10 641 (€ 5897) for the NC to €18 720 (€7905) for RIC (p < .01). The risk of RIC after digestive cancer resection remains high (>15%) and was associated with significantly longer length of stay and higher cost per stay. Although important prevention plans have been implemented in recent years, care strategies are still needed to alleviate the burden on patients and the healthcare system.

Clinical Outcomes for Patients with Brain Metastases from Upper Gastrointestinal Cancer Treated with Stereotactic Radiosurgery

Prior studies have reported outcomes for brain metastases from gastrointestinal (GI) primary cancers treated with stereotactic radiosurgery (SRS); however, most include a majority of colorectal cancer. Few studies specifically evaluate SRS treatment response for brain metastases from upper GI cancers. We report our institutional outcomes for patients with upper GI cancers who were treated with SRS for brain metastases. Patients with an upper GI cancer who underwent SRS for brain metastases between 1991 and 2021 were retrospectively reviewed from a single institution IRB-approved database. The primary endpoint was local failure (LF) and secondary endpoint was overall survival (OS). LF was estimated using the Cumulative Incidence Function with death as a competing risk. Survival analysis was performed with the Kaplan-Meier Method. Predictors of cumulative incidence of LF were assessed using competing risk regression. Forty-nine patients with 107 brain metastases were analyzed. Forty-two (86%) patients were male. The median follow-up time was 6.7 months (range: 0.4-61.7 months) and median OS was 7.5 months (range: 0.9-61.7 months). The median Karnofsky Performance Score (KPS) was 80 (range: 40-100). The primary disease site was esophagus in 87 (81%) lesions, pancreas in 10 (9.3%) lesions, stomach in 5 (4.7%) lesions, liver in 2 (1.9%) lesions, gallbladder in 2 (1.9%) lesions, and small intestine in 1 (0.9%) lesion. The median metastasis size was 1.4 cm (range: 0.3-6.7 cm). The median prescription dose and fraction number were 24 Gy (range: 14-30 Gy) and 1 fraction (range: 1-2 fractions), respectively. The cumulative incidence of LF at 6 and 12 months was 5.6% (95% CI: 2.3-11%) and 12% (95% CI: 6.9-20%), respectively. Overall survival at 6 and 12 months was 59% (95% CI: 50-69%) and 35% (95% CI: 27-46%), respectively. On univariate analysis, female gender (HR = 0.19, 95% CI: 0.06-0.61, p = 0.005), Black race (HR = 0.09, 95% CI: 0.03-0.23, p = <0.001), and larger tumors (HR = 1.35, 95% CI: 1.03-1.78, p = 0.03) were significantly associated with local failure. SRS for brain metastases from upper GI cancers is an appropriate treatment option and provides excellent local control. Unlike prior studies that have reported lower local control rates for all GI cancers with brain metastases treated with SRS, our data show that local failure rates in brain metastases from upper GI cancers specifically are more consistent with previously published data from other disease sites. Further studies evaluating SRS treatment response for brain metastases from GI cancers should separate upper GI and lower GI cancers.

Multi-cancer early detection test in symptomatic patients referred for cancer investigation in England and Wales (SYMPLIFY): a large-scale, observational cohort study

Analysis of circulating tumour DNA could stratify cancer risk in symptomatic patients. We aimed to evaluate the performance of a methylation-based multicancer early detection (MCED) diagnostic test in symptomatic patients referred from primary care. We did a multicentre, prospective, observational study at National Health Service (NHS) hospital sites in England and Wales. Participants aged 18 or older referred with non-specific symptoms or symptoms potentially due to gynaecological, lung, or upper or lower gastrointestinal cancers were included and gave a blood sample when they attended for urgent investigation. Participants were excluded if they had a history of or had received treatment for an invasive or haematological malignancy diagnosed within the preceding 3 years, were taking cytotoxic or demethylating agents that might interfere with the test, or had participated in another study of a GRAIL MCED test. Patients were followed until diagnostic resolution or up to 9 months. Cell-free DNA was isolated and the MCED test performed blinded to the clinical outcome. MCED predictions were compared with the diagnosis obtained by standard care to establish the primary outcomes of overall positive and negative predictive value, sensitivity, and specificity. Outcomes were assessed in participants with a valid MCED test result and diagnostic resolution. SYMPLIFY is registered with ISRCTN (ISRCTN10226380) and has completed follow-up at all sites. 6238 participants were recruited between July 7 and Nov 30, 2021, across 44 hospital sites. 387 were excluded due to staff being unable to draw blood, sample errors, participant withdrawal, or identification of ineligibility after enrolment. Of 5851 clinically evaluable participants, 376 had no MCED test result and 14 had no information as to final diagnosis, resulting in 5461 included in the final cohort for analysis with an evaluable MCED test result and diagnostic outcome (368 [6·7%] with a cancer diagnosis and 5093 [93·3%] without a cancer diagnosis). The median age of participants was 61·9 years (IQR 53·4-73·0), 3609 (66·1%) were female and 1852 (33·9%) were male. The MCED test detected a cancer signal in 323 cases, in whom 244 cancer was diagnosed, yielding a positive predictive value of 75·5% (95% CI 70·5-80·1), negative predictive value of 97·6% (97·1-98·0), sensitivity of 66·3% (61·2-71·1), and specificity of 98·4% (98·1-98·8). Sensitivity increased with increasing age and cancer stage, from 24·2% (95% CI 16·0-34·1) in stage I to 95·3% (88·5-98·7) in stage IV. For cases in which a cancer signal was detected among patients with cancer, the MCED test's prediction of the site of origin was accurate in 85·2% (95% CI 79·8-89·3) of cases. Sensitivity 80·4% (95% CI 66·1-90·6) and negative predictive value 99·1% (98·2-99·6) were highest for patients with symptoms mandating investigation for upper gastrointestinal cancer. This first large-scale prospective evaluation of an MCED diagnostic test in a symptomatic population demonstrates the feasibility of using an MCED test to assist clinicians with decisions regarding urgency and route of referral from primary care. Our data provide the basis for a prospective, interventional study in patients presenting to primary care with non-specific signs and symptoms. GRAIL Bio UK.

Prediction of Stent Failure for Malignant Ureteral Obstruction in Non-Urological Cancer.

To analyze prognostic factors associated with ureteral stent failure and to develop a prediction model for malignant ureteral obstruction (MUO) in patients with non-urological cancers. We retrospectively reviewed patients with non-urological cancers who underwent ureteral stenting or percutaneous nephrostomy (PCN) for MUO between 2006 and 2014. Variables predicting stent failure were identified using Cox regression analysis. Of the 743 patients, 468 (63.0%) underwent ureteral stenting only, and 275 (37.0%) underwent PCN owing to technical (n=215) or functional (n=60) stent failure. The median overall survival was 4 [interquartile range (IQR) 1-11] months, and the median interval duration to stent failure was 2 (IQR 0-7) months. In univariate analysis, lower gastrointestinal cancer, previous radiotherapy to the pelvis, bladder invasion, lower ureteral obstruction, and low previous estimated glomerular filtration rate (eGFR) (<30 mL/min/1.73 m²) were significantly associated with a decreased survival rate. In multivariate analysis, bladder invasion and previous eGFR were significant predictors. With these two predictors, we divided patients into three groups based on their presence: low-risk (neither factor; n=516), intermediate-risk (one factor; n=206), and high-risk (both factors; n=21). The median stent failure-free survival rates of patients in the low-, intermediate-, and high-risk groups were 26 (8-unreached), 1 (0-18), and 0 (0-0) months, respectively (p<0.001). In cases of ureteral obstruction caused by non-urological cancers, patients with bladder invasion and a low eGFR showed poor stent failure-free survival. Therefore, PCN should be considered the primary procedure for these patients.

Cross-Sectional Study for Investigation of the Association Between Modifiable Risk Factors and Gastrointestinal Cancers at a Tertiary Hospital in Ghana.

Malignancies affecting the gastrointestinal tract are among the principal threats to global public health. In Ghana, these cancers are responsible for a significant number of hospitalizations and mortalities at major health facilities across the country. The increasing incidence of these malignancies necessitates an investigation of the association between lifestyle (modifiable risk factors) and these disorders. To determine the association between lifestyle and gastrointestinal cancers of patients attending the Korle Bu Teaching Hospital (KBTH). This was a cross-sectional prospective study where demographic data were obtained from consenting patients diagnosed with gastrointestinal cancer at the oncology and surgical clinics of the KBTH. Diagnostic investigations, gastrointestinal cancer phenotype, year of diagnosis and treatment(s) received were also obtained from the participants. Information on smoking status, alcohol consumption, sources of dietary proteins, daily intake of water, and frequency of fruit intake were also obtained from the participants. Odds ratio and P-values were determined to ascertain whether there might be a significant association between gastrointestinal cancers and specified lifestyle. Colorectal cancers were the most prevalent form of gastrointestinal cancers among the participants. Alcohol consumption or smoking habits were not significantly associated with onset of gastrointestinal cancers among the study participants. There was a significant association but weak correlation between red meat consumption and the colorectal cancer. This study shows consumption of red meat to be a modifiable risk factor that is associated with lower gastrointestinal cancers in the study participants. Further longitudinal studies using large number of participants is needed for confirming the observations from this current study.

Virtual Training on IGRT: A Unique Initiative of a Private Cancer Center from a Developing Country with Regional Academic Collaboration during COVID-19 Pandemic

Purpose/Objective(s)In the year 2020 cancer was identified as the second leading cause of death globally with more than 19 million cancer cases and 10 million cancer deaths. As per GLOBOCAN 2020, the caseload of cancer in Bangladesh was 1,56,775 and the cancer death were 1,08,990. Radiation therapy (RT) is indicated for around 50% of cancer, achieving local control and overall survival benefit. Inadequate number of RT facilities and manpower, huge cancer patient burden, lack of trained manpower is the main barrier for optimum cancer care of Bangladesh. During the COVID pandemic a unique initiative for manpower training in the field of radiation therapy was taken by a private cancer center of Bangladesh, with the regional academic collaboration of a Cancer Institute and Research Center of India. "Virtual training on IGRT" was arranged mainly for radiation therapy technologists (RTT) also with the provision for radiation oncologists (RO) and medical physicists (MP) to attend.Materials/MethodsRetrospective record review of the IGRT training program arranged from 4 September to 9 October 2020 was done.ResultsThe program was designed for five days on five week ends (4 September,11 September, 18 September, 25 September and 9 October 2021) for a duration of three-hours daily. First day was the introductory session which covered Setup, Fusion, Immobilization and Context Setting, followed by site specific discussion. On Day 2. Head and Neck Cancer, Brain Cancer, Day 3. Breast and Thoracic Cancer, Day 4. Upper and Lower Gastrointestinal Cancer, Day 5. Prostate and Cervical Cancer were covered. A number of 245 candidates completed the pre-program online registration (RO- 83, MP-43, RTT-87 and PG Students-32). Among them total 230 attended the virtual program (Day-1-64, Day 2-150, Day 3-100, Day 4-103 and Day 5-103) Total 22 faculties were engaged from the collaborative center of India for this virtual training program where 11 were RO, 4 MP and 9 were RTT. Out of 230 attendants,133 (58%) provided their online feedback. Majority of them (>90%) found the training contents relevant to their daily practice and they opined that this training will help to change their ongoing practice.ConclusionThis first ever initiative of a private Cancer center of Bangladesh with regional academic collaboration could create encouraging response among participants with significant impact on their everyday practice. Participants found the training useful and practice changing. Well-structured, need based more such virtual training program may be arranged in future. This model can be reproduced at other developing countries with the expectation of similar outcome.

Gender profile of principal investigators in a large academic clinical trials group.

IntroductionGender equity in medicine has become a significant topic of discussion due to consistently low female representation in academia and leadership roles. Gender imbalance directly affects patient care. This study examined the gender and craft group of the Principal Investigators (PI) of clinical trials run by the Australasian Gastro-Intestinal Trials Group (AGITG)MethodsPublicly available data was obtained from the AGITG website. Trials were divided into upper, lower gastrointestinal cancer, miscellaneous (neuroendocrine and gastrointestinal stromal tumours). Where multiple PIs were listed, all were counted. Craft group was assigned as surgical, medical, radiation oncology or other.ResultsThere were 69 trials with 89 PI, where 52 trials were represented exclusively by male PIs. Of all PIs, 18 were women (20.2%); all were medical oncologists. Prior to 2005, all PIs were male. The craft group distribution of PIs was: 79% medical oncologists, 12% surgical oncologists, 8% radiation oncologist, 1% nuclear medicine physicians. Regarding trials with multiple PI's, there were 19 in total. Of these, 11 had only male PIs, which included 5 surgeons. Females were more likely to be a co-PI (42%) as opposed to sole PI (18%). There was no gender policy publicly available on the AGITG website.ConclusionsThere is a low percentage of female PIs in academic oncology trials in the portfolio of this large international trials group. No trial was led by a female surgical or radiation oncologist. There is a need to understand the reasons driving the disparity so that specific strategies can be put in place.

Distinct Performance of Methylated SEPT9 in Upper and Lower Gastrointestinal Cancers and Combined Detection with Protein Markers.

Background: The performance of methylated SEPT9 (mSEPT9) in lower gastrointestinal (GI) cancer (colorectal cancer) has been extensively investigated; however, its performance in upper GI cancer (esophageal cancer and gastric cancer) and the comparison with lower GI cancer have rarely been studied. Methods: A total of 1854 subjects, including 344 upper GI cancer patients, 459 lower GI cancer patients, and 1051 noncancer subjects, were recruited in this prospective cohort study. A modified single polymerase chain reaction test for detecting mSEPT9 was used for plasma detection. Results: The sensitivity of mSEPT9 for upper and lower GI cancers was 45.3% and 74.8%, and the corresponding specificities were 85.6% and 86.5%, with areas under curve (AUC) of 0.71 and 0.80, respectively. mSEPT9 exhibited lower sensitivity in stage I than stage II-IV cancer, while no difference in sensitivity was observed for different locations in upper or lower GI cancer. No difference in sensitivity was found among gross classifications, pathological classifications, and differentiation in upper GI cancer, but a higher sensitivity in infiltrative cancer and moderate and poorly differentiated cancers was observed in the lower GI. No difference in sensitivity was found between male and female in both cancers, while sensitivity increased with age for both cancers. Cancer antigen 724 (CA724) showed the highest sensitivity for upper GI cancers, and carcinoembryonic antigen (CEA) showed the highest sensitivity for lower GI cancers. The combination of CA724 with mSEPT9 increased the sensitivity to 67.5% in upper GI cancers, and the combination of mSEPT9 with CEA increased the sensitivity to 85.4% in lower GI cancers, with an AUC of 0.90 and 0.95, respectively. Conclusions: mSEPT9 exhibited a higher sensitivity in lower GI cancers than upper GI cancers. The combination of mSEPT9 with protein markers significantly enhanced the detection sensitivity in both cancers.

Fever of Unknown Origin and Incidence of Cancer.

Diagnostic tools for determining causes of fever of unknown origin (FUO) have improved over time. We examined if cancer incidence among these patients changed over a 20-year period. Population-based cohort study using nationwide Danish registries. We identified individuals diagnosed with FUO (1998-2017) to quantify their excess risk of cancer compared with the general population. Follow-up for cancer started 1 month after FUO. We computed absolute risks and standardized incidence ratios (SIRs) of cancer, and mortality rate ratios adjusted for age, sex, and cancer stage. Among 6620 patients with FUO (46.9% male; median age: 39 years), 343 were diagnosed with cancer (median follow-up: 6.5 years). The 1- to <12-month risk was 1.2%, and the SIR was 2.3 (95% CI, 1.8-2.9). The increased 1- to <12-month SIR was mainly due to an excess of Hodgkin lymphoma (SIR = 41.7) non-Hodgkin lymphoma (SIR = 16.1), myelodysplastic syndrome/chronic myeloproliferative diseases (SIR = 6.0), lower gastrointestinal cancer (SIR = 3.3), and urinary tract cancer (SIR = 2.9). Beyond 1-year follow-up, malignant melanoma, hepatobiliary tract/pancreatic cancer, and brain/CNS/eye cancer were diagnosed more often than expected. The 1- to <12-month cancer SIR attenuated over time, and for the 2013-2017 period we found no excess risk. Patients diagnosed with cancer ≤1 year after FUO had similar mortality to cancer patients without this diagnosis. Patients with FUO have a higher 1- <12-month cancer SIR; thereafter, the incidence for most cancers equals that of the general population. Decreasing SIRs over time suggests improvements in the initial diagnostic workup for FUO.

Prediction Methods of Common Cancers in China Using PCA-ANN and DBN-ELM-BP

Accurate prediction of cancer cases is crucial for diagnosis of cancer at an early stage because a long-lasting chronic disease is harmful to both physical and mental health. While medical data about healthcare and health obtained from questionnaire, the true positive rate of cancers predicted by traditional methods is low. Machine learning can provide a pattern for classification for types of cancer (mainly including lung cancer, liver cancer, upper gastrointestinal cancer, lower gastrointestinal cancer and breast cancer) using instances of early questionnaire screening. The screening covered 3411 respondents in this study. Principal component analysis (PCA) is used to generate attributes, coupled with artificial neural network (ANN) technology to conduct cancer prediction by providing 28 attributes into models. While deep belief network (DBN) is used for unsupervised training and extracting relevant attributes. Extreme learning machine (ELM) optimizes DBN and conducts supervised classification. Back propagation (BP) algorithm conducts supervised fine tuning. Finally, PCA-ANN and DBN-ELM-BP common cancers prediction models are established. The training set and testing set of PCA-ANN model gives 35.29% and 37.5% sensitivity, 98.36% and 98.33% specificity, 97.01% and 97.85% accuracy, an area under the receiver operating characteristic curve (AUC) 0.7245 and 0.7221, respectively. While the training set and testing set of DBN-ELM-BP model gives 58.83% and 62.5% sensitivity, 98.31% and 98.52% specificity, 98.03% and 98.24% accuracy, AUC 0.7747 and 0.7238, respectively. The results show that DBN-ELM-BP model can provide a method to predict the possibility of common cancers, which is non-invasive and economical for clinicians to make diagnostic decisions.

TP7.2.17 Are there any predictable trends in the pattern of two week referrals for suspected gastrointestinal cancers?

Abstract Aims Patients with suspected cancer are referred to secondary care on the “two week wait” pathway. Investigation and management of these patients is resource intensive and puts a significant strain on services. We aim to determine if there are predictable trends in quantity of referrals or cancer detection rates (conversion rates) for suspected upper and lower gastrointestinal cancers. Identifying such trends could guide future resource allocation and provision of services. Methods Two week wait referrals to upper and lower gastrointestinal clinics between 2015 and 2019 were included. The number of referrals and conversion rates were analysed on monthly, quarterly and annual basis. Results Upper GI total referrals: 1094 in 2015 vs 1357 in 2019. Lower GI total referrals: 1827 in 2015 vs. 3278 in 2019. Upper GI conversion rates: 8.8% in 2015 vs. 8.36% in 2019. Lower GI conversion rates: 6.47% in 2015 vs. 4.07% in 2019. There were no identifiable significant trends in referral numbers or conversion rates when analysed on a monthly and quarterly basis. Conclusions The number of two week wait referrals for suspected cancers has shown a sustained year on year increase. Conversion rates for the time period have remained somewhat static and in some cases decreased. Our data shows no evidence of any spikes or troughs in demand related to the time of year. Should demand continue to rise at the current rate then alternate modes of assessment such as telephone assessment clinic or a straight to test approach may become more widespread.

Immune Checkpoint Blockade in Lower Gastrointestinal Cancers: A Systematic Review.

Limited therapy options exist for patients with treatment-refractory metastatic colorectal or anal cancers, prompting investigation into alternative therapies. Immunotherapy in the form of immune checkpoint blockade is one such emerging treatment that has demonstrated promising results in other tumour streams.x This review aims to assess the current use of immune checkpoint blockade in patients with lower gastrointestinal tumours. Embase, Medline and Cochrane databases were searched for included studies. Clinical trials published in English and utilising immune checkpoint blockade for primary tumours situated in the lower gastrointestinal tract were included. Databases were searched for studies reporting on at least one of overall survival, progression-free survival or response to therapy. In total, 972 abstracts were screened, with 10 studies included in the final review. Eight trials (833 patients) assessed immune checkpoint blockade in the setting of colorectal cancers. These included pembrolizumab, nivolumab, durvalumab, atezolizumab, tremelimumab and ipilimumab. A total of 20 patients across all studies achieved a complete response, and 111 patients achieved a partial response to treatment. Two trials (62 patients) assessed immune checkpoint blockade in anal cancer, utilising nivolumab and pembrolizumab. Two patients across both studies achieved a complete response, and 11 patients achieved a partial response. A number of patients with advanced lower gastrointestinal tumours achieved a complete response to treatment for what would otherwise be considered palliative disease. Presented data have highlighted that particular patients may benefit from first-line or combination immunotherapy, and thus, further investigation is warranted to individualise treatment.

Stereotactic Radiosurgery Results for Patients With Brain Metastases From Gastrointestinal Cancer: A Retrospective Cohort Study of 802 Patients With GI-GPA Validity Test

PurposeThe role of stereotactic radiosurgery (SRS) alone for patients with gastrointestinal (GI) cancer has yet to be established based on a large patient series. We analyzed post-SRS treatment results and reappraised whether either the GI graded prognostic assessment (GPA) system or modified-recursive partitioning assessment (M-RPA) system was applicable to our 802 SRS-treated patients with GI cancer with brain metastases. Methods and MaterialsThis was an institutional review board approved retrospective cohort study 2 database comprising 802 patients with GI cancer treated with gamma-knife SRS by 2 experienced neurosurgeons during the 1998 to 2018 period. The Kaplan-Meier method was applied to determine post-SRS survival times, and competing risk analyses were used to estimate cumulative incidences of the secondary endpoints. ResultsThe median survival time (MST; months) after SRS was 5.7. With the GI GPA system, MSTs were 3.5/6.1/7.7/11.0 in the 4 subgroups, that is, 0 to 1.0/1.5 to 2.0/2.5 to 3.0/3.5 to 4.0, respectively (stratified P < .0001). However, there was no significant MST difference between 2 of the subgroups, GI-GPA 1.5 to 2.0 and 2.5 to 3.0 (P = .073). In contrast, using the M-RPA system, 3 plot lines corresponding to the 3 subgroups showed no overlap and the MST differences between the subgroups with M-RPA were 1 + 2a versus 2b (P < .0001) and 2b versus 2c + 3 (P < .0001). Better Karnofsky performance status score, solitary tumor, well-controlled primary cancer, and the absence of extracerebral metastases were shown by multivariable analysis to be significant predictors of longer survival. The crude and cumulative incidences of neurologic death, neurologic deterioration, local recurrence, salvage whole brain radiation therapy, and SRS-related complications did not differ significantly between the 2 patient groups, with upper and lower GI cancers. ConclusionsThis study clearly demonstrated the usefulness of the GI GPA. Patients with GI GPA 1.5 to 2.0 or better or M-RPA 2b or better are considered to be favorable candidates for treatment with SRS alone.

Treatment and prognosis of patients with urinary bladder cancer with other primary cancers: a nationwide population-based study in the Bladder Cancer Data Base Sweden (BladderBaSe).

To study how patients with urinary bladder cancer (UBC) with previous or concomitant other primary cancers (OPCs) were treated, and to investigate their prognosis. Using nationwide population-based data in the Bladder Cancer Data Base Sweden (BladderBaSe), we analysed the probability of treatment with curative intent, and UBC-specific and overall survival (OS) in patients with UBC diagnosed in the period 1997-2014 with or without OPC. The analyses considered the patient's characteristics, UBC tumour stage at diagnosis, and site of OPC. There were 38689 patients, of which 9804 (25%) had OPCs. Those with synchronous OPCs more often had T2 and T3 tumours and clinically distant disease at diagnosis than those with UBC only. Patients with synchronous prostate cancer, female genital cancer and lower gastro-intestinal cancer were more often treated with curative intent than patients with UBC only. When models of survival were adjusted for age at diagnosis, marital status, education, year of diagnosis, Charlson Comorbidity Index and T-stage, UBC-specific survival was similar to patients with UBC only, but OS was lower for patients with synchronous OPC, explained mainly by deaths in OPC primaries with a bad prognosis. OPC is common in patients with UBC. Treatment for UBC, after or in conjunction with an OPC, should not be neglected and carries just as high a probability of success as treatment in patients with UBC only. The needs of patients with UBC and OPC, and optimisation of their treatment considering their complicated disease trajectory are important areas of research.

Clinical and Nutritional Care Pathways of Patients with Malignant Bowel Obstruction: A Retrospective Analysis in a Tertiary UK Center

We describe a retrospective cohort study of patients with malignant bowel obstruction to examine their nutritional care pathways between 1.1.16 and 31.12.16 with readmissions until 31.12.17. Data were analyzed by comparing patients who were referred (R) and not referred (NR) for PN. We identified 72 patients with 117 MBO admissions (mean ± SD age:63.1 ± 13.1yrs, 79% female). 24/72 patients were in R group. Predominant primary malignancies were gynaecological and lower-gastrointestinal cancers (76%). 83% patients had metastases (61% sub-diaphragmatically). All patients were at high-risk of malnutrition and baseline mean weight loss was 7%. Discussion of PN at multidisciplinary team meeting (MDT) (22% vs.5%, P = 0.02) and dietetic contact (94% vs. 41%, P < 0.0001) were more likely to occur in the R group. In 13/69 MBO admissions in NR group, reasons for non-referral were unclear. Median baseline and follow-up weight was similar (55–55.8 kg). Overall survival was 4.7 (1.4–15.2)months, with no differences by referral groups. We compared a sub-sample of patients who ‘may have’ required PN (n = 10) vs. those discharged on home PN (n = 10) and found greater survival in the HPN group (323vs.91 day, P < 0.01). Our findings highlight disparity in care pathways suggesting that nutritional care should be integrated into clinical management discussion(s) at MDT to ensure equal access to nutritional services.

Tumor-informed assessment of molecular residual disease and its incorporation into practice for patients with early and advanced-stage colorectal cancer (CRC-MRD Consortia).

4108 Background: Circulating tumor DNA (ctDNA) testing can be used for the assessment of molecular residual disease (MRD) in patients with early-stage or advanced colorectal cancer (CRC). Prospective evaluation of this methodology in clinical practice has been limited to-date. Methods: A personalized and tumor-informed multiplex PCR assay (Signatera 16-plex bespoke mPCR NGS assay) was used for the detection and quantification of ctDNA for MRD assessment. We analyze and present results from an ongoing early adopter program of ctDNA testing across the spectrum of CRC management. Results: Here we present a total of 250 patients with colon (n=200), rectal (n=40), and other lower gastrointestinal cancers (n =10; anal, appendiceal, small bowel). MRD positivity rates and ctDNA quantification (mean tumor molecules/mL) are shown in Table. ctDNA detection was significantly associated with stage of disease (p&lt;0.0001 Chi-square: 70.33). Additionally, in patients with radiologically measurable active metastatic disease, ctDNA detection rate was 100%. On the contrary, patients with advanced/metastatic disease who had partial response to treatment or no evidence of disease (NED) showed 28.5% and 19.2% of ctDNA-positivity, respectively. Conclusions: This is the first large, real-world study reporting on the results from a clinically validated MRD assay. For the first time we delineate MRD rates and quantify ctDNA concentration in patients with early-stage and advanced CRC. Furthermore, we provide an initial readout that effective ongoing treatment in patients with CRC may be correlated with ctDNA clearance. Ongoing analysis expanded to a cohort of 1200 clinical cases including correlation with genomic and serial testing will be presented. [Table: see text]

Out-patient visits for gastrointestinal cancer at a quaternary South African hospital-trends and geospatial distribution.

This study sought to determine trends in out-patient visits for gastrointestinal cancer (GC) at a quaternary hospital in KwaZulu-Natal (KZN), South Africa; and identify geographical regions which contribute most to GC-related out-patient clinic utilization at this hospital. Data for GC-related outpatient visits over an 11-year period was obtained from the hospital's administrative database. Trends were analyzed using simple regression and trend line analyses. Patient residential postal codes from the administrative database were used to determine the geospatial distribution of complex GC in KZN. Strong increasing trends in GC-related out-patient visits were noted for age >65 years old (R2=0.8014), male (R2=0.7020), female (R2=0.7292), lower GC (R2=0.7094), and rural residence (R2=0.7008). Moderate increasing trends in GC-related out-patient visits were noted for age ≤65 years old (R2=0.6556), upper GC (R2=0.6498), and urban residence (R2=0.6988). The magnitude at which the number of out-patient visits increased was greater for urban residence when compared with rural residence (p=0.006). Urban centers and some regions along the North and South coast of KZN contributed the most toward GC-related out-patient visits. Out-patient visits for complex GC in KZN are increasing. Several regions have been identified for anti-cancer interventions and decentralized out-patient services.