Omission of 5-Fluorouracil Bolus From Multidrug Regimens for Advanced Gastrointestinal Cancers: A Multicenter Cohort Study.

BACKGROUND: 5-Fluorouracil (5-FU) is a major component of gastrointestinal cancer treatments. In multidrug regimens such as FOLFOX, FOLFIRI, and FOLFIRINOX, 5-FU is commonly administered as a bolus followed by an infusion. However, the pharmacologic rationale for incorporating the 5-FU bolus in these regimens is unclear, and there are other effective regimens for gastrointestinal cancers that do not include the bolus. The purpose of this study was to determine whether omission of the 5-FU bolus was associated with a difference in survival and toxicity. METHODS: A real-world database from Flatiron Health was queried for patients with advanced colorectal, gastroesophageal, and pancreatic cancers who received first-line FOLFOX, FOLFIRI, and FOLFIRINOX regimens. Cox proportional hazards and Kaplan-Meier analyses were performed to compare survival outcomes between patients who received the 5-FU bolus and those who did not. Inverse probability of treatment weighted (IPTW) analysis was performed to adjust for treatment selection bias. RESULTS: This study included 11,765 patients with advanced colorectal (n=8,670), gastroesophageal (n=1,481), and pancreatic (n=1,614) cancers. Among all first-line 5-FU multidrug regimens, 10,148 (86.3%) patients received a 5-FU bolus and 1,617 (13.7%) did not. After IPTW analysis, we found that omitting the bolus was not associated with a decrease in overall survival (hazard ratio, 0.99; 95% CI, 0.91-1.07; P=.74). However, omitting the bolus was associated with reductions in neutropenia (10.7% vs 22.7%; P<.01), thrombocytopenia (11.2% vs 16.1%; P<.01), and use of granulocyte colony-stimulating factors after treatment (19.6% vs 29.1%; P<.01). CONCLUSIONS: After adjusting for baseline clinical factors, we found that omission of the 5-FU bolus from FOLFOX, FOLFIRI, and FOLFIRINOX regimens was not associated with decreased survival, but resulted in decreased toxicity and possible health care savings.

Duration of immunotherapy in dMMR/MSI-H metastatic colorectal cancer patients.

BACKGROUND: Immune checkpoint blockade (ICB) has revolutionized treatment of mismatch repair-deficient (dMMR)/microsatellite instability-high (MSI-H) metastatic colorectal cancer (mCRC). However, there is no evidence on the optimal treatment duration. We aimed to compare outcomes of different immunotherapy durations. METHODS: An international multicenter retrospective cohort study of immunotherapy-naïve dMMR/MSI-H mCRC patients who received immunotherapy between 2014-2024. Fixed treatment duration of two years was compared to treatment duration beyond two years. Fixed treatment duration of one year was compared to treatment duration beyond one year. Subgroup analysis was performed for patients who experienced CR. Kaplan-Meier analysis and Cox proportional hazard regression model were used to analyze the effect of all exposure variables on OS. RESULTS: The study cohort included 757 dMMR/MSI-H mCRC patients treated with ICB. Median follow-up time was 46.7 months (IQR 28.5-70.3). There was no statistically significant difference in OS between patients treated for a two-year fixed-duration (n = 83) and those treated beyond two years (n = 139) in both the univariable and multivariable analysis (HR=0.65 95 %CI 0.14-3.07 p = 0.59 and HR=0.61 95 %CI 0.12-3.10 p = 0.6, respectively). The comparison between one-year fixed-duration versus continuing treatment beyond one year included 27 and 330 patients, respectively. For patients who achieved CR, discontinuing treatment after one year was not associated with a negative impact on OS (p = 0.5). CONCLUSIONS: Discontinuing immunotherapy after two years is a reasonable option for dMMR/MSI-H mCRC patients with ongoing response. Treatment discontinuation after one year may be considered for patients achieving CR. Further prospective studies are needed to define the most appropriate duration of therapy.

Extremely high peritoneal cancer index in colorectal peritoneal metastases demonstrates safety and overall survival benefit in selected patients undergoing cytoreductive surgery and heated intraperitoneal chemotherapy.

BACKGROUND: Colorectal peritoneal metastases are a devastating consequence of colorectal cancer (CRC) with extremely poor prognosis. Patients that can undergo complete cytoreduction by cytoreductive surgery and heated intraperitoneal chemotherapy (CRS/HIPEC) have a markedly improved overall survival. Traditionally, patients with extremely high peritoneal cancer index (PCI), PCI >20, are not offered CRS/HIPEC. METHODS: We performed a retrospective analysis of our prospectively maintained CRS/HIPEC database and evaluated all patients with CRC peritoneal metastases between 2012 and 2022. We divided the cohorts between those with low operative PCI (PCI<20) and high operative PCI (PCI =>20). We examined demographic, clinicopathologic data, perioperative, and oncological outcomes between the cohorts. RESULTS: Of the 691 patients who underwent CRS/HIPEC, 289 were evaluable with CRC metastases, 234 with PCI <20 and 43 with PCI => 20. Median radiologic preoperative and operative PCI was 4 and 10 versus 7 and 24.5 in the low and high PCI cohorts, respectively. Operative time was longer (6 vs. 4 h) and blood loss higher (500 vs. 400 mL) in the high PCI cohort. All other demographic, clinicopathological, and operative characteristics were similar. Median disease free survival (DFS) was longer in the low PCI cohort (11.5 vs. 7 months) but overall survival (OS) showed benefit (41.3 vs. 31.8 months), (p = 0.001 and p = 0.189, respectively), comparatively with an only chemotherapy strategy. CONCLUSIONS: Appropriately selected patients with CRC metastases and extremely high PCI demonstrate similar perioperative safety outcomes in experienced tertiary referral centers. Despite a shorter median DFS, these carefully selected patients demonstrated similar median OS.

Exogenous Insulin Therapy Is Associated with the Risk of Advanced Colorectal Adenoma in Patients with Diabetes Mellitus.

BACKGROUND/AIMS: Exogenous insulin therapy increases systemic exposure to insulin which may promote the development of colorectal neoplasia. We sought to evaluate the association between exogenous insulin therapy and the incidence of advanced adenoma in type 2 diabetes mellitus. METHODS: A retrospective cohort study was conducted from January 1, 2007, to January 1, 2018, in a regional health system serving the United States Philadelphia metropolitan area, Central New Jersey, and South Central Pennsylvania. Study patients consisted of a random sample of patients with type 2 diabetes mellitus aged 40-80 years who had undergone two rounds of colonoscopy examinations. The exposure was cumulative duration of insulin therapy (i.e., no use, 1-365 days and > 365 days). The outcome was time to incident advanced adenoma. RESULTS: Of the 975 eligible patients, 184 patients accumulated > 365 days of insulin therapy before the follow-up colonoscopy. The mean (standard deviation) duration between the two rounds of colonoscopy examination was 5.1 (2.9) years among the insulin users and 5.3 (3.9) years among non-users. Compared to no insulin exposure, receiving > 365 days of insulin therapy was associated with an increased incidence of advanced adenoma (adjusted hazard ratio [aHR] 4.84, 95% confidence interval [CI] 2.82-8.30), right-sided advanced adenoma (aHR 5.48, 95% CI 2.90-10.35), and 3 or more adenomas (aHR 2.61, 95% CI 1.46-4.69) at the follow-up colonoscopy examination. CONCLUSION: Insulin therapy is associated with an increased risk of advanced adenoma and may serve as a novel risk-stratification factor to enhance the efficiency of existing colorectal cancer screening and surveillance programs.

Immunotherapy in mismatch repair-deficient metastatic colorectal cancer - Outcome and novel predictive markers.

BACKGROUND: This study aims to assess predictive markers for response to immunotherapy in dMMR/MSI-H metastatic colorectal cancer (mCRC) patients. MATERIALS AND METHODS: A study using two prospective cohorts from MD Anderson Cancer Center and Sheba Medical Center of consecutive patients with dMMR/MSI-H mCRC that were treated with immunotherapy between 2014-2022. Primary outcome was progression-free survival (PFS) and secondary outcome was overall response rate (ORR). Evaluated predictors included ECOG-PS score, RAS/BRAF status, single-agent versus doublet immunotherapy, metastatic sites, disease burden, and CEA levels prior to treatment initiation. Kaplan-Meier analysis and Cox proportional hazard regression model were used to analyze the effect of exposure variables on PFS. RESULTS: The study included 153 patients. Median follow-up time was 26 months (IQR 11-48). Median PFS was 51.6 months (95%CI 38.1-NR) and ORR was 58.1%. In a univariate analysis, male sex was associated with worse PFS with a HR of 1.67 (95% CI 1.00-2.79); Right-sided tumors were associated with improved PFS with a HR of 0.56 (95% CI 0.32-0.97); Liver or lung metastasis were associated with worse PFS with HRs of 2.35 (95%CI 1.43-3.88) and 2.30 (95%CI 1.31-4.04), respectively; ECOG-PS score ≥ 2, CEA levels ˃5 µg/L prior to treatment initiation and ≥ 3 metastatic sites were associated with worse PFS with HRs of 2.09 (95%CI 0.98-4.47), 2.23 (95%CI 1.30-3.81) and 3.11 (95%CI 1.61-6.03), respectively. Liver or lung metastasis remained significant in a multivariable model. CONCLUSIONS: Extent of disease (worse PFS with high CEA, poor ECOG-PS and ≥3 metastatic sites) and disease location (worse PFS with liver or lung metastasis and left sided tumor) were associated with immunotherapy outcome in dMMR/MSI-H mCRC.

Role of the microbiota in response to and recovery from cancer therapy.

Our understanding of how the microbiota affects the balance between response to and failure of cancer treatment by modulating the tumour microenvironment and systemic immune system has advanced rapidly in recent years. Microbiota-targeting interventions in patients with cancer are an area of intensive investigation. Promisingly, phase I-II clinical trials have shown that interventions such as faecal microbiota transplantation can overcome resistance to immune checkpoint blockade in patients with melanoma, improve therapeutic outcomes in treatment-naive patients and reduce therapy-induced immunotoxicities. Here, we synthesize the evidence showing that the microbiota is an important determinant of both cancer treatment efficacy and treatment-induced acute and long-term toxicity, and we discuss the complex and inter-related mechanisms involved. We also assess the potential of microbiota-targeting interventions, including bacterial engineering and phage therapy, to optimize the response to and recovery from cancer therapy.

Analysis of BRCA1- and BRCA2-Related Pancreatic Cancer and Survival.

This cohort study compares the outcomes of patients with BRCA1 and BRCA-related pancreatic cancers using 2 large data sets.

Early Systemic Anti-neoplastic Treatment Post SARS-CoV-2 Infection in Patients with Breast Cancer.

INTRODUCTION: It is unclear how soon after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection it is safe to resume systemic anti-neoplastic treatment in patients with cancer. We assessed the risk of admissions or postponed treatment cycle in vaccinated patients with breast cancer receiving early systemic anti-neoplastic treatment following SARS-CoV-2 infection. METHODS: This was a retrospective cohort study conducted during Omicron SARS-CoV-2 outbreak in Israel, January-July 2022. SARS-CoV-2 cohort included 30 vaccinated patients with breast cancer with SARS-CoV-2 infection 7-14 days prior to systemic treatment. All patients had resolved symptoms and a negative antigen detection test on the day of treatment. The pre-coronavirus disease 2019 (COVID-19) pandemic cohort consisted of 49 matched patients with breast cancer treated with systemic anti-neoplastic agents during 2019. RESULTS: In 30 vaccinated patients with breast cancer who received systemic anti-neoplastic treatment 7-14 days following SARS-CoV-2 infection, compared with 49 matched patients treated in 2019, the rates of emergency department (ED) visits (13% versus 6%, respectively), hospitalizations (3% versus 4%), next cycle of treatment given per protocol (90% versus 88%), and death (0% versus 0%) were similar. CONCLUSION: In a cohort of vaccinated patients with breast cancer who received systemic anti-neoplastic treatment 7-14 days after SARS-CoV-2 infection, we did not observe substantially higher rates of ED visits, hospitalizations, or deaths compared with a similar cohort of pre-COVID-19 patients with breast cancer. Most patients received the next planned cycle on time. Early resumption of systemic anti-neoplastic treatment following SARS-CoV-2 infection in vaccinated patients with breast cancer with a negative antigen test at the day of treatment appeared to be safe. Additional data on larger cohorts and other malignancies are needed to support clinical guidelines.

Tumor Differentiation as a Prognostic Marker in Clinically Staged T1bN0 Esophageal Adenocarcinoma.

Current guidelines recommend that clinically staged T1N0 esophageal cancers are to be referred to surgery or endoscopic resection. Using the National Cancer Database, we identified 733 individuals with clinically staged T1N0 esophageal carcinoma, who underwent upfront surgery and did not receive any prior treatment. We assessed upstaging, which was defined as ≥ T2 disease or positive lymph nodes. Poorly differentiated adenocarcinomas were associated with upstaging, whereas squamous cell carcinomas were not. Specifically, the percentage of upstaging among individuals with clinically staged T1b and poorly differentiated tumor was 33.8%. Therefore, clinically staged T1bN0 poorly differentiated esophageal adenocarcinomas are at high risk for upstaging following surgery.

Combination Treatment of Intratumoral Vidutolimod, Radiosurgery, Nivolumab, and Ipilimumab for Microsatellite Stable Colorectal Carcinoma With Liver Metastases.

INTRODUCTION: Microsatellite stable metastatic colorectal cancer (MSS mCRC) is largely refractory to immune checkpoint inhibition. We hypothesized that a combination of intratumoral TLR9 agonist, radiosurgery and dual PD-1 and CTLA-4 blockade would induce a local focus of immune stimulation, evoking a systemic immune response. PATIENTS AND METHODS: In this phase I single-institution study, patients with MSS mCRC were treated with a priming dose of s.c vidutolimod, 3 intratumoral injections of vidutolimod and radiosurgery, combined with nivolumab and ipilimumab. Cytokine levels were measured at baseline and at 7 (± 2) weeks. Patients were accrued to 4 consecutive cohorts: (1) Safety run-in without radiosurgery, (2) Radiosurgery prior to intratumoral therapy, (3) Radiosurgery prior to intratumoral therapy with a condensed timeline, and (4) Radiosurgery to extrahepatic lesion following completion of intratumoral therapy. RESULTS: A total of 19 patients were accrued. Median age was 59 years (range 40-71), 68% were male, median number of previous systemic treatments was 3 (range 2-5). None of the patients responded, aside from 1 patient, attributed to high tumor mutational burden. Grade 3 liver toxicity was reported in 0%, 0%, 75%, and 17% in cohorts 1 to 4, respectively. Systemic levels of CXCL10 and IL-10 increased, with a median of 407 versus 78 pg/mL (P = .01), and 66 versus 40 pg/mL (P = .03), respectively. CONCLUSIONS: The combination of intratumoral vidutolimod, radiosurgery, nivolumab and ipilimumab was not found to be efficacious in MSS mCRC with liver metastases. The juxtaposition of liver irradiation and intratumoral vidutolimod injection was associated with high hepatic toxicity.

Fecal Microbiota Transplantation as a Cancer Therapeutic.

ABSTRACT: For decades, cancer research and treatment focused on the cellular level, viewing cancer as a genetic disease of cell transformation. In the era of chemotherapy and radiotherapy, studies from the second half of the 19th century suggesting an association between the microbiota and cancer were almost neglected. The main focus of the field was limited to identification of specific viruses and bacteria that may serve as direct carcinogens leading to the recognition of 7 viruses (i.e., human papillomavirus, hepatitis B virus, and Kaposi sarcoma-associated herpesvirus) and 1 bacterium (Helicobacter pylori) as human carcinogens by the International Agency for Research on Cancer (https://monographs.iarc.who.int/agents-classified-by-the-iarc/). Shortly after the publication of the first draft of the human genome project in February 2001, the Nobel laureate microbiologist Joshua Lederberg raised the question: "Is human identity all in the genes?" It took more than a decade later and the development of multiomic techniques to confirm that his answer "each one of us is a small ecological community" was correct (Lederberg J. Keynote Address: Beyond the Genome. Brooklyn Law Rev 67). This ecological notion became relevant to cancer prevention, prediction, and treatment following the immunotherapy revolution and the understanding of the metabolic and immunologic roles of the microbiota in health and disease. Recently, the microbiota was recognized as an emerging hallmark of cancer following a large body of research showing its role in tumorigenesis, treatment efficacy and toxicity, and initial data regarding the role of microbial modulation in cancer therapy (Cancer Discov 2022;12(1):31-46). In the current review, we will focus on the role of fecal microbiota transplantation, the first microbial modulation technique that is used mainly in low-complexity conditions such as recurrent Clostridium difficile infections (Aliment Pharmacol Ther 2017;46(5):479-493), as a possible cancer therapeutic. However, to better understand the suggested roles of fecal microbiota transplantation in medical oncology, we first need to understand cancer as an ecological niche and the role of the microbiota in tumorigenesis and cancer treatment, specifically immunotherapy.

Evaluating sex as a predictive marker for response to bevacizumab in metastatic colorectal carcinoma: Pooled analysis of 3,369 patients in the ARCAD database.

BACKGROUND: Previous studies suggest a possible sex-specific response to bevacizumab in metastatic colorectal carcinoma (mCRC), showing a benefit in males, while the effect in females is less significant. METHODS: Data from 3369 patients with mCRC enrolled on four first-line randomised trials testing chemotherapy with or without bevacizumab (2000-2007) were pooled. Association between sex and progression-free survival and overall survival (OS) was evaluated by stratified Cox regression model, adjusted for potential confounders. Predictive value was evaluated by interaction effect between sex and treatment. In a pre-planned secondary analysis, analyses were stratified using an age cut point of 60 years to evaluate the possible role of menopausal-related effects. RESULTS: Bevacizumab was associated with an improved median OS in males and females, with a 2.3- and 0.6-months benefit, respectively. Stratified by age, bevacizumab resulted in improved OS in males at both age categories. In females at or above the age of 60 (n = 731), bevacizumab resulted in improved OS. However, in females below the age of 60 (n = 634), OS benefit did not reach statistical significance (adjusted hazard ratio = 0.94, 95% confidence interval 0.74-1.20). CONCLUSIONS: Our results confirmed the OS benefit from the addition of bevacizumab to first-line chemotherapy in mCRC in both sexes. Among females, the benefit was less than 1 month. For females under the age of 60, there was no survival benefit. These findings could be used to relieve financial toxicity or be redistributed within healthcare systems for other health-related purposes.

Pelvic Peritonectomy Poorly Affects Outcomes in Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Colorectal Metastases.

BACKGROUND: Constraints of pelvic anatomy render complete cytoreduction (CRS) challenging. The aim of this study is to investigate the impact of pelvic peritonectomy during CRS/HIPEC on colorectal peritoneal metastasis (CRPM) patients' outcomes. METHODS: This is a retrospective analysis of a prospectively maintained CRS/hyperthermic intraperitoneal chemotherapy (HIPEC) database. The analysis included 217 patients with CRPM who had a CRS/HIPEC between 2014 and 2021. We compared perioperative and oncological outcomes of patients with pelvic peritonectomy (PP) (n = 63) to no pelvic peritonectomy (non-PP) (n = 154). RESULTS: No differences in demographics were identified. The peritoneal cancer index (PCI) was higher in the PP group with a median PCI of 12 vs. 6 in the non-PP group (p < 0.001). Operative time was 4.9 vs. 4.3 h in the PP and non-PP groups, respectively (p = 0.63). Median hospitalization was longer in the PP group at 12 vs. 10 days (p = 0.007), and the rate of complications were higher in the PP group at 57.1% vs. 39.6% (p = 0.018). Pelvic peritonectomy was associated with worse disease-free (DFS) and overall survival (OS) with 3-year DFS and OS of 7.3 and 46.3% in the PP group vs. 28.2 and 87.8% in the non-PP group (p = 0.028, p .> 0.001). The univariate OS analysis identified higher PCI (p = 0.05), longer surgery duration (p = 0.02), and pelvic peritonectomy (p < 0.001) with worse OS. Pelvic peritonectomy remained an independent prognostic variable, irrespective of PCI, on the multivariate analysis (p < 0.001). CONCLUSIONS: Pelvic peritonectomy at the time of CRS/HIPEC is associated with higher morbidity and worse oncological outcomes. These findings should be taken into consideration in the management of patients with pelvic involvement.

Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy in Elderly is Safe and Effective.

INTRODUCTION: An increasing proportion of elderly patients (EP) are undergoing Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy (CRS/HIPEC). They have increased comorbidities and perioperative risk. Current literature is deficient in describing the outcomes of EP undergoing CRS/HIPEC. MATERIALS AND METHODS: A retrospective review of our prospectively maintained CRS/HIPEC database analyzed perioperative and oncological outcomes of EP (>70 y) compared to younger patients (YP) (<60 y). RESULTS: Of 500 CRS/HIPEC patients, 62 EP and 210 YP were included. Median age was 73 y in EP and 46 y in YP. Demographic, clinical, operative, and perioperative outcomes were similar between groups. American Society of Anesthesiologists > 3 was more prevalent in the EP with 88.2% versus 54.8% in the YP (P < 0.001). Comorbidities were higher in the EP with 87.1% versus 39.0% in the YP (P < 0.001). Peritoneal Cancer Index score was similar with a median of 9. All postoperative and severe complications were similar with 55.2% and 17.1% in the YP and 64.5% and 21.0% in the EP (P = 0.242; P = 0.448). Postoperative mortality was similar with 1.5% in the YP and 5.0% in the EP (P = 0.134). In colorectal primary patients, median overall and disease-free survival was 61.8 and 12.9 mo in the YP and 64.6 and 11.3 mo in the EP (P = 0.363; P = 0.845). CONCLUSIONS: Despite a significant age difference, increased comorbidities, worse American Society of Anesthesiologists, and similar Peritoneal Cancer Index burden, we found no significant differences in perioperative complications or oncological benefit in elderly CRS/HIPEC patients. EP appear to have similar perioperative and oncological outcomes as YP.

Natural History and Management of Small-Bowel Obstruction in Patients After Cytoreductive Surgery and Intraperitoneal Chemotherapy.

BACKGROUND: Small-bowel obstruction (SBO) after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) is a common complication associated with re-admission that may alter patients' outcomes. Our aim was to characterize and investigate the impact of bowel obstruction on patients' prognosis. METHODS: This was a retrospective analysis of patients with SBO after CRS/HIPEC (n = 392). We analyzed patients' demographics, operative and perioperative details, SBO re-admission data, and long-term oncological outcomes. RESULTS: Out of 366 patients, 73 (19.9%) were re-admitted with SBO. The cause was adhesive in 42 (57.5%) and malignant (MBO) in 31 (42.5%). The median time to obstruction was 7.7 months (range, 0.5-60.9). Surgical intervention was required in 21/73 (28.7%) patients. Obstruction eventually resolved (spontaneous or by surgical intervention) in 56/73 (76.7%) patients. Univariant analysis identified intraperitoneal chemotherapy agents: mitomycin C (MMC) (HR 3.2, p = 0.003), cisplatin (HR 0.3, p = 0.03), and doxorubicin (HR 0.25, p = 0.018) to be associated with obstruction-free survival (OFS). Postoperative complications such as surgical site infection (SSI), (HR 2.2, p = 0.001) and collection (HR 2.07, p = 0.015) were associated with worse OFS. Multivariate analysis maintained MMC (HR 2.9, p = 0.006), SSI (HR 1.19, p = 0.001), and intra-abdominal collection (HR 2.19, p = 0.009) as independently associated with OFS. While disease-free survival was similar between the groups, overall survival (OS) was better in the non-obstruction group compared with the obstruction group (p = 0.03). CONCLUSIONS: SBO after CRS/HIPEC is common and complex in management. Although conservative management was successful in most patients, surgery was required more frequently in patients with MBO. Patients with SBO demonstrate decreased survival.

Outcomes of Stable Lung Colorectal Metastases on Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy.

BACKGROUND: Cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC) have demonstrated benefit in patients with colorectal peritoneal metastases (CRPM). Traditionally, extraperitoneal disease is considered a contraindication to CRS/HIPEC. Stable lung metastases in patients with colorectal cancer often have an indolent course, while the presence of untreated peritoneal metastases poorly affects short-term survival. We sought to evaluate the outcomes of patients undergoing CRS/HIPEC for peritoneal disease with known stable lung metastases. METHODS: We retrospectively reviewed our prospectively maintained CRS/HIPEC database. In 2017, we adopted a policy of considering patients with stable lung metastases for CRS/HIPEC as part of multidisciplinary treatment. We compared the oncologic outcome and safety of CRS/HIPEC with peritoneal only (PM) against patients with peritoneal and lung metastases (PLM). RESULTS: Our database includes 570 patients with CRS/HIPEC of which 174 with CRPM that underwent CRS/HIPEC, 18 with preoperatively diagnosed peritoneal and lung metastases. The demographics of the PM and PLM group were similar with the exception of operative time that was longer in the PLM group. Median PCI of the cohort was 7, similar in both groups (p = 0.89). Three-year overall survival (OS) of PLM patients was 68%, compared to 71% in PM (p = 0.277). Three-year progression-free survival (PFS) rate was 20% in PLM and 23% in PM (p = 0.688). CONCLUSIONS: Presence of stable lung metastases from colorectal cancer in patients with CRPM does not appear to affect the outcomes of CRS/HIPEC. Patients with stable lung disease should be considered for CRS/HIPEC after multidisciplinary discussion.

Serological response to a third booster dose of BNT162b2 COVID-19 vaccine among seronegative cancer patients.

BACKGROUND AND AIM: The BNT162b2 COVID-19 vaccine (Pfizer/BioNTech), given as a two-dose series, 3 weeks apart, elicits a serological response in 84-98% of patients with cancer, even if administered while undergoing anticancer treatments. Herein, we report the impact of a third (booster) dose of BNT162b2, delivered 6 months following the second vaccine dose. METHODS: This pilot study included four patients with cancer who were seronegative after two vaccine doses, and received a third (booster) dose of BNT162b2 at 6 months following the second vaccine dose. The four patients received the three vaccine doses between December 2020 and July 2021. Samples were evaluated with an enzyme-linked immunosorbent assay (ELISA) that detects IgG (Immunoglobulin G) antibodies against the RBD (receptor-binding domain) of SARS-CoV-2. RESULTS: At a mean time of 19 days (ranges 7-28) after the second vaccination, all four patients were seronegative for RBD-IgG. However, at a mean time of 21 days (ranges 20-22) after the third dose, three out of the four patients (75%) were now seropositive. Mean RBD-IgG titers were increased after the third vaccine dose from 0.37 to 2.81 (Student's t-test, p = 0.05, two-sided). CONCLUSIONS: Although limited by the small sample size, our findings suggest that a third (booster) dose administered to patients with cancer, who remain seronegative despite two doses of BNT162b2, may be efficacious in eliciting an antibody response.