Low preoperative psoas muscle mass index is a risk factor for distal cholangiocarcinoma recurrence after pancreatoduodenectomy: a retrospective analysis

BACKGROUND

This study aimed to investigate whether preoperative muscle mass is associated with the recurrence of distal cholangiocarcinoma after pancreatoduodenectomy (PD).

METHODS

We retrospectively examined 88 patients who had undergone PD for distal cholangiocarcinoma. The preoperative psoas muscle mass index (PMI) was measured using computed tomography as an index of muscle mass. We performed multivariate analysis of factors influencing early recurrence and developed a prognostic survival model using independent risk factors for recurrence.

RESULTS

The cut-off PMI values for recurrence within 1 year of surgery, determined from the receiver operating characteristic curve, were 5.90 cm²/m² in males and 3.98 cm²/m² in females. Multivariate analysis of effects associated with early recurrence within 1 year indicated that low PMI (odds ratio [OR] 9.322; 95% confidence interval [CI] 2.832 - 30.678; p = 0.0002) and lymph node metastasis (OR 5.474; 95% CI 1.620 - 18.497; p = 0.0062) were independent risk factors, and the median recurrence-free survival (RFS) of the low and high PMI groups were 21.6 and 81.0 months, respectively (p = 0.0214). The median RFS for zero, one, and two risk factors of low PMI and lymph node metastasis were as follows: zero variables, median not reached; one variable, 15.3 months; two variables: 6 months.

CONCLUSIONS

Low preoperative PMI may be a risk factor for distal cholangiocarcinoma recurrence after PD.

TRIAL REGISTRATION

The Institutional Review Board of St. Marianna University School of Medicine approved this study prior to commencement of data collection and analysis on October 9, 2020 (IRB no. 5006) and waived the informed consent requirement.

Lipid-Based Nanoparticle Formulation of Diallyl Trisulfide Chemosensitizes the Growth Inhibitory Activity of Doxorubicin in Colorectal Cancer Model: A Novel In Vitro, In Vivo and In Silico Analysis

Garlic’s main bioactive organosulfur component, diallyl trisulfide (DATS), has been widely investigated in cancer models. However, DATS is not suitable for clinical use due to its low solubility. The current study seeks to improve DATS bioavailability and assess its chemopreventive and chemosensitizing properties in an AOM-induced colorectal cancer model. The polyethylene glycol coated Distearoylphosphatidylcholine/Cholesterol (DSPC/Chol) comprising DATS-loaded DATSL and doxorubicin (DOXO)-encapsulated DOXL liposomes was prepared and characterized. The changes in the sensitivity of DATS and DOXO by DATSL and DOXL were evaluated in RKO and HT-29 colon cancer cells. The synergistic effect of DATSL and DOXL was studied by cell proliferation assay in the combinations of IC₁₀, IC₂₅, and IC₃₅ of DATSL with the IC₁₀ of DOXL. AOM, DATSL, and DOXL were administered to different groups of mice for a period of 21 weeks. The data exhibited ~93% and ~46% entrapment efficiency of DATSL and DOXL, respectively. The size of sham liposomes was 110.5 nm, whereas DATSL and DOXL were 135.5 nm and 169 nm, respectively. DATSL and DOXL exhibited significant sensitivity in the cell proliferation experiment, lowering their IC₅₀ doses by more than 8- and 14-fold, respectively. However, the DATSL IC₁₀, IC₂₅, and IC₃₅ showed escalating chemosensitivity, and treated the cells in combination with DOXL IC₁₀. Analysis of histopathological, cancer marker enzymes, and antioxidant enzymes revealed that the high dose of DATSL pretreatment and DOXL chemotherapy is highly effective in inhibiting AOM-induced colon cancer promotion. The combination of DATSL and DOXL indicated promise as a colorectal cancer treatment in this study. Intermolecular interactions of DATS and DOXO against numerous cancer targets by molecular docking indicated MMP-9 as the most favourable target for DATS exhibiting binding energy of −4.6 kcal/mol. So far, this is the first research to demonstrate the chemopreventive as well as chemosensitizing potential of DATSL in an animal model of colorectal cancer.

The Effect of Liposomal Diallyl Disulfide and Oxaliplatin on Proliferation of Colorectal Cancer Cells: In Vitro and In Silico Analysis

Diallyl disulfide (DADS) is one of the main bioactive organosulfur compounds of garlic, and its potential against various cancer models has been demonstrated. The poor solubility of DADS in aqueous solutions limits its uses in clinical application. The present study aimed to develop a novel formulation of DADS to increase its bioavailability and therapeutic potential and evaluate its role in combination with oxaliplatin (OXA) in the colorectal cancer system. We prepared and characterized PEGylated, DADS (DCPDD), and OXA (DCPDO) liposomes. The anticancer potential of these formulations was then evaluated in HCT116 and RKO colon cancer cells by different cellular assays. Further, a molecular docking-based computational analysis was conducted to determine the probable binding interactions of DADS and OXA. The results revealed the size of the DCPDD and DCPDO to be 114.46 nm (95% EE) and 149.45 nm (54% EE), respectively. They increased the sensitivity of the cells and reduced the IC₅₀ several folds, while the combinations of them showed a synergistic effect and induced apoptosis by 55% in the cells. The molecular docking data projected several possible targets of DADS and OXA that could be evaluated more precisely by these novel formulations in detail. This study will direct the usage of DCPDD to augment the therapeutic potential of DCPDO against colon cancer in clinical settings.

Predictive Nomogram for the Prediction of Early Recurrence of Colorectal Cancer

Aim

The prognosis of colorectal cancer (CRC) individuals after curative resection is not satisfactory due to the early recurrence. We sought to identify the affecting features of early recurrence in CRC patients.

Methods

A total of 3500 CRC patients underwent curative resection were retrospectively incorporated into our study. Among them, 246 patients exhibited tumor recurrence: 121 had early recurrence (≤1 year after operation) and 125 had late recurrence (>1 year after operation). A total of 246 CRC patients with recurrence were randomly assigned into the training group (N=177) or validation group (N=69) based on the ratio of 7:3. LASSO COX regression and support vector machine (SVM) were utilized to screen for the significant clinical indexes associated with the presence of early recurrence. Recurrent nomogram was created based on the above informative parameters to predict the probability of early recurrence.

Results

Proportion of advanced TNM stage, platelet count, systemic immune-inflammation index (SII), mean corpuscular hemoglobin concentration (MCHC), CA-199, CA-125, lactate dehydrogenase, total bile acid (TBA), urea nitrogen were significantly higher in early recurrence group compared with that in late recurrence group. Results from LASSO COX regression and support vector machine (SVM) revealed that TNM stage, CA-199, CA125, SII and TBA were strong predictors for the presence of early recurrence among postoperative CRC patients in the training group. The recurrent nomogram based on the five predictors exhibited good predictive performance as calculated by C-index (0.846, 95% CI 0.789-0.902 in the training group and 0.799, 95% CI 0.697-0.902 in the validation group) for the prediction of early recurrence. Moreover, the recurrent nomogram exhibited not only encouraging calibration ability, but also great clinical utility both in the training group and validation group.

Conclusion

TNM stage, CA-199, CA125, SII and TBA were closely correlated with the presence of early recurrence of CRC patients. The recurrent nomogram held well predictive ability for the identification of CRC patients with early recurrence.

Clinicopathological and Molecular Features of Patients with Early and Late Recurrence after Curative Surgery for Colorectal Cancer

Simple Summary

Colorectal cancer patients with early recurrence had advanced pathological node categories, pathological tumor, node, metastasis stages, adjuvant chemotherapy treatment, a worse overall survival rate, more liver metastases and more APC mutations than those with late recurrence. Patients with right-sided colon cancer tended to have early recurrence than those with left-sided colon cancer or rectal cancer. The postrecurrence survival rates were not significantly different between patients with early and late recurrence, which was observed in right-sided colon, left-sided colon and rectum. Multivariate analysis showed that old age, early recurrence, multiple-site recurrence and BRAF and NRAS mutations were independent prognostic factors.

Abstract

Background: Few reports have investigated genetic alterations between patients with early and late recurrence following curative surgery for colorectal cancer (CRC). Methods: A total of 1227 stage I–III CRC patients who underwent curative resection were included retrospectively. Among them, 236 patients had tumor recurrence: 139 had early (<2 years after surgery) and 97 had late (≥2 years after surgery) recurrence. Clinicopathological features and genetic alterations were compared between the two groups. Results: Compared to those with late recurrence, patients with early recurrence were more likely to have advanced pathological node (N) categories; tumor, node, metastasis (TNM) stages; adjuvant chemotherapy treatment; liver metastases; APC mutations; and worse five-year overall survival rates. Patients with right-sided colon cancer were more likely to develop early recurrence than were those with left-sided colon cancer or rectal cancer. Regarding rectal cancer, patients with early recurrence were more likely to be at advanced pathological N categories and TNM stages than those with late recurrence. Multivariate analysis revealed old age, early recurrence, multiple-site recurrence, and BRAF and NRAS mutations to be independent prognostic factors. Conclusion: CRC patients with early recurrence have a worse OS rate and more APC mutations than those with late recurrence.

Synergistic Inhibition of Drug-Resistant Colon Cancer Growth with PI3K/mTOR Dual Inhibitor BEZ235 and Nano-Emulsioned Paclitaxel via Reducing Multidrug Resistance and Promoting Apoptosis

BACKGROUND

Colon cancer is a top lethal cancer in man and women worldwide and drug resistance is the major cause of cancer-related death. Combinational therapy and drug delivery with nanoparticles have been shown to effectively overcome drug resistance in many cancers. We previously reported that nanoemulsion (NE) loaded paclitaxel (PTX) and BEZ235 could synergistically inhibit colon cancer cell growth.

PURPOSE

To investigate whether NE loaded PTX and BEZ235 can overcome drug resistance and synergistically inhibit drug-resistant colon cancer cell growth in vitro and in vivo.

METHODS

The in vitro treatment effect on cell viability was assayed using CCK8 kit, cell morphological change was detected by β-tubulin immunofluorescence staining, drug resistance-related proteins were analyzed by Western blotting, and in vivo tumor growth test was performed in nude mice xeno-transplanted with 2 drug-resistant colon cancer cell lines HCT116-LOHP and HT29-DDP.

RESULTS

Both cell lines were sensitive to PTX but relatively insensitive to BEZ235. PTX combined with BEZ235 synergistically inhibited the proliferation of both cell lines. Nanoemulsion loaded PTX (NE-PTX) reduced the IC50 of PTX to approximately 2/5 of free PTX, indicating a high inhibitory efficacy of NE-PTX. When NE-PTX combined with a low concentration of BEZ235 (50 nM), the IC50 was decreased to approximately 2/3 of free PTX. Moreover, NE-PTX+BEZ235 treatment increased apoptosis, decreased Pgp and ABCC1 expression, and reduced tumor weights compared to the single drug treatment and the control group. These results suggest that nanoemulsion loaded PTX+BEZ235 can overcome drug resistance and improve the inhibitory effect on cancer cell proliferation and tumor growth.

CONCLUSION

Our study thus provides a possible new approach to treat colon cancer patients with drug resistance.

Long-Term Outcomes of Radical Surgery for Transverse Colon Cancer Staged from I to IIIC

Background

No study has reported the risk factors associated with the prognosis of patients with transverse colon cancer. Therefore, we aimed to demonstrate the long-term outcomes of transverse colon cancer patients undergoing radical surgery and explore the prognostic factors.

Materials and Methods

The clinical data of a total of 366 patients with transverse colon cancer staged from I to IIIC undergoing radical surgery from February 1992 to May 2017 were retrospectively analyzed. Clinicopathological features were recorded, and univariate and multivariate analyses were conducted to evaluate the association between the factors and overall survival (OS) as well as disease-free survival (DFS). Kaplan–Meier curves were generated to assess the association between TNM stage and OS and DFS, respectively.

Results

The median follow-up time was 62 months, and the 5-year OS and DFS rates were 87.5% and 86.5%, respectively. In addition, a significant difference was also found in the OS and DFS curves according to TNM stage. The N classification, vascular invasion, differentiation, preoperative CA199, preoperative CA125 and preoperative AFP were significantly associated with OS according to univariate analysis, while N classification and differentiation were independent prognostic factors for OS according to multivariate analysis (both P < 0.05). Similarly, N classification, vascular invasion, differentiation, preoperative CA199, preoperative CA125, and preoperative AFP were statistically correlated with DFS according to univariate analysis, while N classification and preoperative CA199 were independent prognostic factors for DFS according to multivariate analysis (both P < 0.05).

Conclusion

N classification was an independent factor for both OS and DFS, while differentiation and CA199 were independent prognostic factors only for OS and DFS, respectively.

Disease characteristics and treatment patterns of Chinese patients with metastatic colorectal cancer: a retrospective study using medical records from China

Background

Colorectal cancer (CRC) is the third most prevalent cancer in China but few large-scale studies were conducted to understand CRC patients. The current study is aimed to gain a real-world perspectives of CRC patients in China.

Methods

Using electronic medical records of sampled patients between 2011 and 2016 from 12 hospitals in China, a retrospective cohort study was conducted to describe demographics and disease prognosis of CRC patients, and examine treatment sequences among metastatic CRC (mCRC) patients. Descriptive, comparative and survival analyses were conducted.

Results

Among mCRC patients (3878/8136, 48%), the fluorouracil, leucovorin, and oxaliplatin (FOLFOX) and other oxaliplatin-based regimens were the most widely-used first-line treatment (42%). Fluorouracil, leucovorin, irinotecan (FOLFIRI) and other irinotecan-based regimens dominated the second-line (40%). There was no a dominated regimen for the third-line. The proportion of patients receiving chemotherapy with targeted biologics increased from less than 20% for the first- and second- lines to 34% for the third-line (p < 0.001). The most common sequence from first- to second-line was from FOLFOX and other oxaliplatin-based regimens to FOLFIRI and other irinotecan-based regimens (286/1200, 24%).

Conclusions

Our findings reflected a lack of consensus on the choice of third-line therapy and limited available options in China. It is evident o continue promoting early CRC diagnosis and to increase the accessibility of treatment options for mCRC patients. As the only nationwide large-scale study among CRC and mCRC patients before more biologics became available in China, our results can also be used as the baseline to assess treatment pattern changes before and after more third-line treatment were approved and covered into the National Health Insurance Plan in China between 2017 and 2018.

Molecular correlates and prognostic value of tmTNF-α expression in colorectal cancer of 5-Fluorouracil-Based Adjuvant Therapy

Transmembrane tumor necrosis factor-α (tmTNF-α) is known to induce the activation of NF-κB to protect tumor cells. Upregulation of tmTNF-α leads to resistance to apoptosis and induces drug resistance in breast cancer. However, the expression of tmTNF-α in colorectal cancer (CRC) and its association with clinical outcome in CRC have remained unclear. In this study, we examined the tmTNF-α expression in CRC by immunohistochemistry and western blotting, assessed the prognostic value of tmTNF-α related to the recurrence/metastasis and survival of stage II/III CRC by the Kaplan-Meier survival curve and Cox regression model, and also explored the role of tmTNF-α expression on the chemotherapeutic efficacy of 5-Fluorouracil by flow cytometry assay and cell counting kit-8 (CCK-8) in vitro. Overall, we found that 77 (78.6%) out of 98 patients exhibited higher tmTNF-α expression in the CRC tissues comparing with the adjacent tissues. The tmTNF-α expression was correlated with Differentiation (P = 0.019), TNM stage (P = 0.039), Lymph nodes metastasis (P = 0.024) and Lymphovascular invasion (P = 0.027) but not related with Age (P = 0.617), Gender (P = 0.625), Tumor location (P = 0.138), Perforation/Obstruction (P = 1.000), Depth of invasion (P = 0.327), and microsatellite instability status (P = 0.150). The prognostic analyses showed that high tmTNF-α expression patients was significantly associated with decreased Disease-Free Survival (P = 0.0209) and Overall Survival (P = 0.0163). CCK-8 results suggested that the tmTNF-α influenced the chemotherapeutic effect of 5-Fluorouracil on colon cancer cells. Altogether, these data indicated the stageII/III CRC patients with high tmTNF-α expression were more likely to have a worse prognosis than patients with low tmTNF-α expression and tmTNF-α may influence the chemotherapeutic effect of 5-Fluorouracil. The mechanism for these observations warrants further study.

Diet and Colorectal Cancer Risk in Asia--a Systematic Review

Diet is one of the major factors that can exert a majorly influence on colorectal cancer risk. This systematic review aimed to find correlations between various diet types, food or nutrients and colorectal cancer risk among Asian populations. Search limitations included Asian populations residing in Asia, being published from the year 2008 till present, and written in the English language. A total of 16 articles were included in this systematic review. We found that red meats, processed meats, preserved foods, saturated/animal fats, cholesterol, high sugar foods, spicy foods, tubers or refined carbohydrates have been found by most studies to have a positive association with colorectal cancer risk. Inversely, calcium/dairy foods, vitamin D, general vegetable/fruit/fiber consumption, cruciferous vegetables, soy bean/soy products, selenium, vitamins C,E and B12, lycophene, alpha-carotene, beta-carotene, folic acid and many other vitamins and minerals play a protective role against colorectal cancer risk. Associations of fish and seafood consumption with colorectal cancer risk are still inconclusive due to many varying findings, and require further more detailed studies to pinpoint the actual correlation. There is either a positive or no association for total meat consumption or white meats, however their influence is not as strong as with red and processed meats.

Colorectal Cancer Patient Characteristics, Treatment and Survival in Oman--a Single Center Study

BACKGROUND

Colorectal cancer is the most common gastrointestinal cancer in Oman with an increasing incidence. We here report the presenting features, treatment outcomes and survival in a University hospital in Oman and compare our data with regional and international studies.

MATERIALS AND METHODS

Medical records of patients with colorectal cancer were reviewed retrospectively between June 2000 and December 2013 and were followed until June 2014.

RESULTS

A total of 162 patients were diagnosed with colorectal cancer. The majority were males (58.6%), with a median age of 56 years. Rectum was involved in 29.6% of patients, followed by ascending and sigmoid colon. The majority of patients had stage III (42.6%) and stage IV (32.7%) disease at presentation. K-Ras status was checked for 79 patients, and 41 (51.9%) featured the wild type. Median relapse free survival was 22 months. Median overall survival for all patients was 43 months. Observed 5 year overall survival (OS) for stages I, II and III was 100%, 60% and 60% respectively. On Log rank univariate analysis, age, BMI, diabetes, hypertension, metformin use, stage, clinical nodal status for rectal cancer, pathological T and nodal status, site of metastasis, surgical intervention, chemotherapy, radiotherapy, chemotherapy regimen, no of cycles of chemotherapy, response, RFS, site of recurrence and administration of 2nd line chemotherapy were significant factors affecting OS. On Cox regression multivariate analysis none of the factors independently affected the OS.

CONCLUSIONS

The majority of patients present with advanced disease and at young age. The survival rates are comparable to the published regional and international literature.

MicroRNA expression profile in patients with stage II colorectal cancer: a Turkish referral center study

BACKGROUND

There are increasing data about microRNAs (miRNA) in the literature, providing abundant evidence that they play important roles in pathogenesis and development of colorectal cancer. In this study, we aimed to investigate the miRNA expression profiles in surgically resected specimens of patients with recurrent and non-recurrent colorectal cancer.

MATERIALS AND METHODS

The study population included 40 patients with stage II colorectal cancer (20 patients with recurrent tumors, and 20 sex and age matched patients without recurrence), who underwent curative colectomy between 2004 and 2011 without adjuvant therapy. Expression of 16 miRNAs (miRNA-9, 21, 30d, 31, 106a, 127, 133a, 133b, 135b, 143, 145, 155, 182, 200a, 200c, 362) was verified by quantitative real-time polymerase chain reaction (qRT-PCR) in all resected colon cancer tissue samples and in corresponding normal colonic tissues. Data analyses were carried out using SPSS 15 software. Values were statistically significantly changed in 40 cancer tissues when compared to the corresponding 40 normal colonic tissues (p<0.001). MiR-30d, miR-133a, miR-143, miR-145 and miR-362 expression was statistically significantly downregulated in 40 resected colorectal cancer tissue samples (p<0.001). When we compared subgroups, miRNA expression profiles of 20 recurrent cancer tissues were similar to all 40 cancer tissues. However in 20 non-recurrent cancer tissues, miR-133a expression was not significantly downregulated, moreover miR-133b expression was significantly upregulated (p<0.05).

CONCLUSIONS

Our study revealed dysregulation of expression of ten miRNAs in Turkish colon cancer patients. These miRNAs may be used as potential biomarkers for early detection, screening and surveillance of colorectal cancer, with functional effects on tumor cell behavior.

Prognostic factors and the role of adjuvant chemotherapy in post-curative surgery for Dukes B and C colon cancers and survival outcomes: a Malaysian experience

BACKGROUND

Adjuvant chemotherapy improves survival in Dukes C colon cancers post-curative resection. However, the evidence for a role with Dukes B lesions remains unproven despite frequent use for disease characterized by poor prognostic features. In view of limited Asia-specific data, this study aimed to determine survival outcomes and identify prognostic factors in a tertiary teaching hospital in Malaysia.

MATERIALS AND METHODS

A total of 116 subjects who underwent curative surgery with and without adjuvant chemotherapy for Duke B and C primary colon adenocarcinomas diagnosed from 2004-2009 were recruited and data were collected retrospectively. Five-year overall survival (OS) and disease free survival (DFS) were analysed using Kaplan-Meier survival analysis and log-rank (Mantel-Cox) test. Prognostic factors were determined using Cox proportional hazards regression with both univariate and multivariate analyses.

RESULTS

The survival analysis demonstrated a 5-year OS of 74.0% for all patients, with 74.9% for Dukes C subjects receiving chemotherapy compared to 28.6% in those not receiving chemotherapy (p=0.001). For Dukes B disease, the 5-year survival rate was 82.6% compared to 75.0% for subjects receiving and not receiving chemotherapy, respectively (p=0.17). Independent prognostic factors identified included a CEA level more than 3.5 ng/ml (hazard ratio (HR)=4.78; p=0.008), serosal involvement (HR=3.75; p=0.028) and completion of chemotherapy (HR= 0.20; p=0.007).

CONCLUSIONS

In a regional context, this study supports current evidence from the West that adjuvant chemotherapy improves survival in Dukes C colon cancers post curative surgery. However, although a clear benefit has yet to be proven for Dukes B disease, our results suggest survival improvement in selected cases.

Factors affecting prognosis in metastatic colorectal cancer patients

BACKGROUND

Colorectal cancer (CRC) is a major cause of mortality in developed countries, and it is the third most frequent malignancy in Turkey. There are many biological, genetic, molecular, and tissue-derived prognostic factors for CRCs. In this study, we evaluated prognostic factors in patients who were metastatic at diagnosis or progressed to metastatic disease during follow-up.

PATIENTS AND METHODS

This study included 116 patients with malignancies either in the colon or rectum. Of these, 65 had metastatic disease at diagnosis, and 51 progressed to metastatic disease during the course of the disease. The parameters evaluated were age, gender, comorbidity, performance status and stage of the disease at the beginning, localization, history of surgery, chemotherapy regimen, response to first-line treatment, K-RAS status, site and number of metastases, expression of tumor predictors (CEA, CA19-9), and survival times. A multivariate analysis conducted with factors that considered statistically significant in the univariate analysis.

FINDINGS

Median age was 56 (32-82) years and the male/ female ratio was 80/36. Eleven patients were at stage II, 40 at stage III, and 65 at stage IV at diagnosis. Twenty three patients had tumor in the right colon, 48 in the left colon, and 45 in the rectum. Ninety seven patients were operated, and 27 had surgical metastasectomy. Ninety three patients received targeted therapy. At the end of follow-up, 61 patients had died, and 55 survived. Metastatic period survival times were longer in the adjuvant group, but the difference did not reach the level of statistical significance (adjuvant group: median 29 months, metastatic group: median 22 months; p=0.285). In the adjuvant group before the metastatic first-line therapy, CEA and CA 19-9 levels were significiantly lower compared to the metastatic group (p<0.005). We also found that patients with elevated tumor predictor (CEA, CA 19-9) levels before the first-line therapy had significiantly poorer prognosis and shorter survival time. Survival was significiantly better with the patients who were younger than 65 years of age, had better initial performance status, a history of primary surgery and metastatectomy, and single site of metastasis. Those who benefitted from the first-line therapy were K-RAS wild type and whose tumor markers (CEA, CA 19-9) were not elevated before the first line therapy.

CONCLUSIONS

Among the patients with metastatic CRC, those who benefited from first-line therapy, had history of metastasectomy, were K-RAS wild type and had low CA 19-9 levels before the first-line therapy, showed better prognosis independent of other factors.

Melatonin as a treatment for gastrointestinal cancer: a review

Gastrointestinal cancer is a disease that affects the population worldwide with high morbidity and mortality. Melatonin, an endogenously produced molecule, may provide a defense against a variety of cancer types. In particular, the ability of melatonin to inhibit gastrointestinal cancer is substantial. In this review, we first clarify the relationship between the disruption of the melatonin rhythm and gastrointestinal cancer (based on epidemiologic surveys and animal and human studies) and summarize the preventive effect of melatonin on carcinogenesis. Thereafter, the mechanisms through which melatonin exerts its anti-gastrointestinal cancer actions are explained, including inhibition of proliferation, invasion, metastasis, and angiogenesis, and promotion of apoptosis and cancer immunity. Moreover, we discuss the drug synergy effects and the role of melatonin receptors involved in the growth-inhibitory effects on gastrointestinal cancer. Taken together, the information compiled here serves as a comprehensive reference for the anti-gastrointestinal cancer actions of melatonin that have been identified to date and will hopefully aid in the design of further experimental and clinical studies and increase the awareness of melatonin as a therapeutic agent in cancers of the gastrointestinal tract.