Perioperative Systemic Therapy Versus Cytoreductive Surgery and HIPEC Alone for Resectable Colorectal Peritoneal Metastases: Patient-Reported Outcomes of a Randomized Phase II Trial.

BACKGROUND: As part of a randomized phase II trial in patients with isolated resectable colorectal peritoneal metastases (CPMs), the present study compared patient-reported outcomes (PROs) of patients treated with perioperative systemic therapy versus cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) alone. Also, PROs of patients receiving perioperative systemic therapy were explored. PATIENTS AND METHODS: Eligible patients were randomized to perioperative systemic therapy (experimental) or CRS-HIPEC alone (control). PROs were assessed using EORTC QLQ-C30, QLQ-CR29, and EQ-5D-5L questionnaires at baseline, after neoadjuvant treatment (experimental), and at 3 and 6 months postoperatively. Linear mixed modeling was used to compare five predefined PROs (visual analog scale, global health status, physical functioning, fatigue, C30 summary score) between arms and to longitudinally analyze PROs in the experimental arm. RESULTS: Of 79 analyzed patients, 37 (47%) received perioperative systemic therapy. All predefined PROs were comparable between arms at all timepoints and returned to baseline at 3 or 6 months postoperatively. The experimental arm had worsening of fatigue [mean difference (MD) + 14, p = 0.001], loss of appetite (MD + 15, p = 0.003), hair loss (MD + 18, p < 0.001), and loss of taste (MD + 27, p < 0.001) after neoadjuvant treatment. Except for loss of appetite, these PROs returned to baseline at 3 or 6 months postoperatively. CONCLUSIONS: In patients with resectable CPM randomized to perioperative systemic therapy or CRS-HIPEC alone, PROs were comparable between arms and returned to baseline postoperatively. Together with the trial's previously reported feasibility and safety data, these findings show acceptable tolerability of perioperative systemic therapy in this setting.

Diagnostic performance of MRI for staging peritoneal metastases in patients with colorectal cancer after neoadjuvant chemotherapy.

INTRODUCTION: MRI improves the selection of patients with colorectal cancer (CRC) and peritoneal metastases (PM) for cytoreductive surgery by accurately assessing the extent of PM reflected as the peritoneal cancer index (PCI). The performance of MRI after neoadjuvant chemotherapy (NACT) for staging PM, however is unknown. The purpose of this study was to determine whether MRI could also accurately determine the PCI after NACT. MATERIALS AND METHODS: This was a single-centre, retrospective study of patients with PM from CRC or appendiceal origin who received NACT followed by diffusion-weighted (DW)-MRI and surgery from January 2016 to February 2021. Two radiologists assessed the PCI on restaging DW-MRI (mriPCI). The reference standard was the surgical PCI (sPCI). The main outcome was the diagnostic performance of restaging DW-MRI in predicting whether patients were eligible for cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC), defined as a PCI < 21 with metastases on resectable locations. If CRS-HIPEC was performed, the resected peritoneal lesions were assessed and correlated with the final pathological PCI (pPCI). RESULTS: Thirty-three patients were included. Both readers correctly detected all 23 patients with resectable disease. Eight out of ten patients with unresectable disease during staging surgery were detected by both readers with MRI. The intraclass correlation (ICC) between both readers was excellent (0⋅87 (95% CI: 0⋅75 to 0⋅93)). The ICC between pPCI and mriPCI was 0⋅74 (0⋅49-0⋅88) and 0⋅82 (0⋅66-0⋅91) for the 2 readers. Surgical PCI (sPCI) had a similar correlation as mriPCI with pPCI 0⋅82 (0⋅62- 0⋅92)) and 0⋅81 (0⋅57-0⋅92)). CONCLUSION: DW-MRI is a promising tool to reassess the peritoneal cancer index after neoadjuvant chemotherapy.

Treatment of PERItoneal disease in Stomach Cancer with cytOreductive surgery and hyperthermic intraPEritoneal chemotherapy: PERISCOPE I initial results.

BACKGROUND: The role of cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (HIPEC) in gastric cancer is unknown. This non-randomized dose-finding phase I-II study was designed to assess the safety and feasibility of HIPEC, following systemic chemotherapy, in patients with gastric cancer and limited peritoneal dissemination. The maximum tolerated dose of normothermic intraperitoneal docetaxel in combination with a fixed dose of intraperitoneal oxaliplatin was also explored. METHODS: Patients with resectable cT3-cT4a gastric adenocarcinoma with limited peritoneal metastases and/or tumour-positive peritoneal cytology were included. An open HIPEC technique was used with 460 mg/m2 hyperthermic oxaliplatin for 30 min followed by normothermic docetaxel for 90 min in escalating doses (0, 50, 75 mg/m2 ). RESULTS: Between 2014 and 2017, 37 patients were included. Of 25 patients who completed the full study protocol, four were treated at dose level 1 (0 mg/m2 docetaxel), six at dose level 2 (50 mg/m2 ) and four at dose level 3 (75 mg/m2 ). At dose level 3, two dose-limiting toxicities occurred, both associated with postoperative ileus. Thereafter, another 11 patients were treated at dose level 2, with no more dose-limiting toxicities. Based on this, the maximum tolerated dose was 50 mg/m2 intraperitoneal docetaxel. Serious adverse events were scored in 17 of 25 patients. The reoperation rate was 16 per cent (4 of 25) and the treatment-related mortality rate was 8 per cent (2 patients, both in dose level 3). CONCLUSION: Gastrectomy combined with cytoreductive surgery and HIPEC was feasible using 460 mg/m2 oxaliplatin and 50 mg/m2 normothermic docetaxel.

ANTECEDENTES: El papel de la cirugía citorreductora (cytoreductive surgery, CRS) combinado con la quimioterapia intraperitoneal hipertérmica (hyperthermic intraperitoneal chemotherapy, HIPEC) en el cáncer gástrico no está definido. Este estudio fase I-II no aleatorizado de escalado de dosis fue diseñado para evaluar la seguridad y la viabilidad de HIPEC, después de la quimioterapia sistémica, en pacientes con cáncer gástrico con diseminación peritoneal limitada. Además, se exploró la máxima dosis tolerada (maximum tolerated dose, MTD) de docetaxel intraperitoneal normotérmico en combinación con una dosis fija de oxaliplatino intraperitoneal. MÉTODOS: Se incluyeron pacientes con adenocarcinoma gástrico cT3-cT4a resecable con metástasis peritoneales limitadas y/o citología peritoneal positiva. Se utilizó una técnica HIPEC abierta con 460 mg/m2 de oxaliplatino hipertérmico (30 minutos) seguido de docetaxel normotérmico (90 minutos) en dosis crecientes (0, 50, 75 mg/m2 ). RESULTADOS: Entre 2014 y 2017, se incluyeron 37 pacientes. De los 25 pacientes que completaron la totalidad del protocolo del estudio, 4 pacientes fueron tratados en el nivel de dosis 1 (0 mg/m2 de docetaxel), 6 pacientes en el nivel de dosis 2 (50 mg/m2 ) y 4 pacientes en el nivel de dosis 3 (75 mg/m2 ). En el nivel de dosis 3, se produjeron dos casos de toxicidad limitante de dosis (dose-limiting toxicities, DLTs), ambas asociadas con un íleo postoperatorio. Posteriormente, otros 11 pacientes fueron tratados con el nivel de dosis 2, y no se produjeron más DLTs. La MTD de docetaxel intraperitoneal fue de 50 mg/m2 . Se registraron efectos adversos graves en 17 de 25 pacientes. La tasa de reoperación fue del 16% (n = 4) y la mortalidad relacionada con el tratamiento fue del 8% (n = 2; ambos en el nivel de dosis 3).

Factors influencing long-term survival after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for pseudomyxoma peritonei originating from appendiceal neoplasms.

Background: Pseudomyxoma peritonei (PMP) is a rare disease, most commonly of appendiceal origin. Treatment consists of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). The aim of this study was to identify prognostic factors for recurrence and survival. Methods: This was an observational study using a prospectively designed database containing consecutive patients with PMP originating from the appendix, undergoing CRS-HIPEC at a tertiary referral centre between 1996 and 2015. Histopathological slides were reassessed. Cox regression was used for multivariable analyses. Results: Of 225 patients identified, 36 (16·0 per cent) were diagnosed with acellular mucin, 149 (66·2 per cent) had disseminated peritoneal adenomucinosis (DPAM) and 40 (17·8 per cent) had peritoneal mucinous carcinomatosis (PMCA). The 5-year overall survival (OS) rates were 93, 69·8 and 55 per cent respectively. Recurrence was observed in 120 patients (53·3 per cent), 39 of whom (17·3 per cent) were treated with a second CRS-HIPEC procedure. Factors independently associated with poor disease-free survival were six or seven affected regions (hazard ratio (HR) 6·01, 95 per cent c.i. 2·04 to 17·73), incomplete cytoreduction (R2a resection: HR 1·67, 1·05 to 2·65; R2b resection: HR 2·00, 1·07 to 3·73), and more than threefold raised carcinoembryonic antigen (CEA) and/or carbohydrate antigen (CA) 19-9 level (HR 2·31, 1·30 to 4·11). Factors independently associated with poorer OS were male sex (HR 1·74, 1·09 to 2·77), incomplete cytoreduction (R2a resection: HR 1·87, 1·14 to 3·08; R2b resection: HR 2·28, 1·19 to 4·34), and more than threefold raised CEA and/or CA19-9 level (HR 2·89, 1·36 to 6·16). Conclusion: CEA and CA19-9 levels raised more than threefold above the upper limit identify patients with PMP of appendiceal origin and poorer survival.

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy versus palliative systemic chemotherapy in stomach cancer patients with peritoneal dissemination, the study protocol of a multicentre randomised controlled trial (PERISCOPE II).

BACKGROUND: At present, palliative systemic chemotherapy is the standard treatment in the Netherlands for gastric cancer patients with peritoneal dissemination. In contrast to lymphatic and haematogenous dissemination, peritoneal dissemination may be regarded as locoregional spread of disease. Administering cytotoxic drugs directly into the peritoneal cavity has an advantage over systemic chemotherapy since high concentrations can be delivered directly into the peritoneal cavity with limited systemic toxicity. The combination of a radical gastrectomy with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has shown promising results in patients with gastric cancer in Asia. However, the results obtained in Asian patients cannot be extrapolated to Western patients. The aim of this study is to compare the overall survival between patients with gastric cancer with limited peritoneal dissemination and/or tumour positive peritoneal cytology treated with palliative systemic chemotherapy, and those treated with gastrectomy, CRS and HIPEC after neoadjuvant systemic chemotherapy. METHODS: In this multicentre randomised controlled two-armed phase III trial, 106 patients will be randomised (1:1) between palliative systemic chemotherapy only (standard treatment) and gastrectomy, CRS and HIPEC (experimental treatment) after 3-4 cycles of systemic chemotherapy.Patients with gastric cancer are eligible for inclusion if (1) the primary cT3-cT4 gastric tumour including regional lymph nodes is considered to be resectable, (2) limited peritoneal dissemination (Peritoneal Cancer Index < 7) and/or tumour positive peritoneal cytology are confirmed by laparoscopy or laparotomy, and (3) systemic chemotherapy was given (prior to inclusion) without disease progression. DISCUSSION: The PERISCOPE II study will determine whether gastric cancer patients with limited peritoneal dissemination and/or tumour positive peritoneal cytology treated with systemic chemotherapy, gastrectomy, CRS and HIPEC have a survival benefit over patients treated with palliative systemic chemotherapy only. TRIAL REGISTRATION: clinicaltrials.gov NCT03348150 ; registration date November 2017; first enrolment November 2017; expected end date December 2022; trial status: Ongoing.

The impact of radiological retroperitoneal lymphadenopathy on survival after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for colorectal peritoneal metastases.

OBJECTIVES: To investigate the impact of retroperitoneal lymphadenopathy (RPLP) on pre-operative CT scan on overall survival (OS) and disease-free survival (DFS) after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) for peritoneal metastases (PM) of colorectal cancer. BACKGROUND: In patients with PM enlarged retroperitoneal lymph nodes (RPLP) are usually considered extra-regional lymph node metastases and therefore these patients may be excluded from CRS-HIPEC. This is a clinical dilemma since it is often hard to obtain histology from these nodes. METHODS: In this multicenter, retrospective study all consecutive patients with colorectal PM treated with CRS-HIPEC between 2004 and 2013 were included. The preoperative CT-scan was re-analyzed for the presence of RPLP based on the radiological appearance of enlarged lymph nodes. Outcomes were OS and DFS. Kaplan-Meier methods and Cox regression modeling were used to analyze the impact of RPLP on OS and DFS. RESULTS: In 25 of 401 patients (6.1%) RPLP was observed on the preoperative CT-scan. Patient, tumor and surgical characteristics did not statistically significantly differ between groups with and without RPLP. After a median follow-up of 46 months, the one-, three- and five-year survival was 80%, 59%, 38% and 90%, 50%, 36% in the group with and without RPLP respectively. Median OS (47 vs. 35 months, logrank: p = 0.70) and median DFS (14 vs. 15 months, logrank: p = 0.81) did not statistically significantly differ between groups. In multivariable analysis, RPLP did not significantly influence survival. CONCLUSION: Enlarged retroperitoneal lymph nodes on a pre-operative CT-scan should not automatically exclude patients from CRS-HIPEC.

Diffusion-weighted MRI assessment of the peritoneal cancer index before cytoreductive surgery.

BACKGROUND: Patients with limited peritoneal metastases from colorectal cancer may be candidates for an aggressive surgical approach including cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). Selection is based on surgical inspection during laparoscopy or laparotomy. The aim of this study was to investigate whether diffusion-weighted MRI (DW-MRI) can be used to select patients for CRS-HIPEC. METHODS: This was a prospective study at a tertiary referral centre. Patients with confirmed or suspected colorectal peritoneal metastases scheduled for exploratory laparotomy or laparoscopy were eligible. Two radiologists assessed the peritoneal cancer index (PCI) on CT (CT-PCI) and DW-MRI (MRI-PCI). The reference standard was PCI at surgery. Radiologists were blinded to the surgical PCI and to each other's findings. The main outcome was the accuracy of DW-MRI in predicting whether patients had resectable disease (PCI less than 21) or not. RESULTS: Fifty-six patients were included in the study, of whom 49 could be evaluated. The mean(s.d.) PCI at surgery was 11·27(7·53). The mean MRI-PCI was 10·18(7·07) for reader 1 and 8·59(7·08) for reader 2. Readers 1 and 2 correctly staged 47 of 49 and 44 of 49 patients respectively (accuracy 96 and 90 per cent). Both readers detected all patients with resectable disease with a PCI below 21 at surgery (sensitivity 100 per cent). No patient was overstaged. The intraclass correlation (ICC) between readers was excellent (ICC 0·91, 95 per cent c.i. 0·77 to 0·96). MRI-PCI had a stronger correlation with surgical PCI (ICC 0·83-0·88) than did CT-PCI (ICC 0·39-0·44). CONCLUSION: DW-MRI is a promising non-invasive tool to guide treatment selection in patients with peritoneal metastases from colorectal cancer.

Histopathological and molecular classification of colorectal cancer and corresponding peritoneal metastases.

BACKGROUND: Patients with colorectal peritoneal carcinomatosis have a very poor prognosis. The recently developed consensus molecular subtype (CMS) classification of primary colorectal cancer categorizes tumours into four robust subtypes, which could guide subtype-targeted therapy. CMS4, also known as the mesenchymal subtype, has the greatest propensity to form distant metastases. CMS4 status and histopathological features of colorectal peritoneal carcinomatosis were investigated in this study. METHODS: Fresh-frozen tissue samples from primary colorectal cancer and paired peritoneal metastases from patients who underwent cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy were collected. Histopathological features were analysed, and a reverse transcriptase-quantitative PCR test was used to assess CMS4 status of all collected lesions. RESULTS: Colorectal peritoneal carcinomatosis was associated with adverse histopathological characteristics, including a high percentage of stroma in both primary tumours and metastases, and poor differentiation grade and high-grade tumour budding in primary tumours. Furthermore, CMS4 was significantly enriched in primary tumours with peritoneal metastases, compared with unselected stage I-IV tumours (60 per cent (12 of 20) versus 23 per cent; P = 0.002). The majority of peritoneal metastases (75 per cent, 21 of 28) were also classified as CMS4. Considerable intrapatient subtype heterogeneity was observed. Notably, 15 of 16 patients with paired tumours had at least one CMS4-positive tumour location. CONCLUSION: Significant enrichment for CMS4 was observed in colorectal peritoneal carcinomatosis. Surgical relevance Cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) improves survival of selected patients with colorectal peritoneal carcinomatosis, but recurrence is common. Histopathological and molecular analysis of colorectal peritoneal carcinomatosis could provide clues for development of novel therapies. In this study, colorectal peritoneal carcinomatosis was found to be enriched for tumours with high stromal content and CMS4-positive status. To further improve prognosis for patients with colorectal peritoneal carcinomatosis, therapies that target tumour-stroma interaction could be added to CRS-HIPEC.

Safety of intraperitoneal Mitomycin C versus intraperitoneal oxaliplatin in patients with peritoneal carcinomatosis of colorectal cancer undergoing cytoreductive surgery and HIPEC.

BACKGROUND: Colorectal peritoneal carcinomatosis (PC) is commonly treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). There is an ongoing international debate about which intraperitoneal chemotherapeutic agent is preferred, Mitomycin C (MMC) or oxaliplatin. We questioned whether the type of chemotherapeutic agent influenced postoperative complication rates or short-term survival. METHODS: In this retrospective cohort study patients with colorectal PC who underwent CRS-HIPEC between January 2010 and December 2016 were included. Until March 2014 patients had preferentially been treated with MMC and thereafter with oxaliplatin in an iso-osmotic glucose/electrolyte dialysis (Dianeal®) carrier solution. Main outcomes were postoperative complications, disease free survival (DFS) and overall survival (OS). Survival analyses and multivariable analyses were performed. RESULTS: One hundred four patients received MMC and 73 patients oxaliplatin. Postoperative complications did not differ between groups (44.2% (MMC) versus 43.8% (oxaliplatin); P = 0.958). Median DFS was 12.5 months (IQR 6.4-32.4) in the MMC-group and 13.1 months (IQR 6.1-NA) in the oxaliplatin-group (P = 0.669). Median OS was 37.2 months (IQR 17.2-NA) in the MMC-group and 29.4 months (IQR 17.0-NA) in the oxaliplatin-group (P = 0.764). The type of chemotherapeutic agent did not influence OS in multivariable analysis (oxaliplatin versus MMC HR 1.09 (95%CI 0.58-2.06)). The HIPEC-phase was shorter for oxaliplatin (median 32 (IQR 31-34) versus 91 min (IQR 90-92) for MMC (P < 0.001)). CONCLUSION: Intraperitoneal oxaliplatin reduced the chemoperfusion time when compared to intraperitoneal MMC without adversely influencing complication rates or short-term survival. It may therefore be the preferential drug in CRS-HIPEC procedures for colorectal PC.

Cytoreduction and hyperthermic intraperitoneal chemotherapy: The learning curve reassessed.

BACKGROUND: CytoReductive Surgery and Hyperthermic IntraPEritoneal Chemotherapy (CRS-HIPEC) is now the preferred treatment of many peritoneal surface malignancies. In this retrospective study we aimed to analyze how several performance indicators changed during the first 100 CRS-HIPEC procedures in hospitals which recently introduced this treatment, and compare those with an experienced institution. METHODS: The first consecutive 100 CRS-HIPEC procedures of three institutions were compared to those of the pioneer hospital. The training provided by the pioneer hospital consisted of hands-on training during the first ten procedures; hereafter guidance was available on consult basis. Operation characteristics, morbidity and completeness of cytoreduction were evaluated by case sequence. Locally-estimated-scatter-plot smoothing was used to evaluate the learning curve. RESULTS: From four institutions 372 cases were included. A macroscopic complete cytoreduction was reached in 66% of the cases in the pioneer hospital and in 86% in the new hospitals (p < 0.001). Complete cytoreduction rates were higher at start off in the new institutions compared with the experienced institution and increased significantly in the first 100 procedures. The new hospitals started with lower morbidity than the experienced hospital, which did not significantly decrease during the study period. CONCLUSION: New institutions that were trained and mentored by an experienced CRS-HIPEC hospital performed better from the beginning with regard to complete cytoreduction and morbidity rate with than the experienced center. An improvement in complete cytoreduction rate during the first 100 procedures was observed in the new institutions.

Treatment of ovarian metastases of colorectal and appendiceal carcinoma in the era of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

AIM: To compare outcome of women with ovarian metastasis who underwent cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) to outcome of women without ovarian metastasis who underwent CRS-HIPEC. METHODS: A prospective CRS-HIPEC database was searched to identify women with surgically treated colorectal carcinoma between 2000 and 2012. Patients with ovarian metastasis were identified and patients with peritoneal carcinomatosis but without ovarian metastasis were included as control cases. RESULTS: 75 patients with macroscopic ovarian metastasis underwent CRS-HIPEC with curative intent, while 50 female patients without ovarian metastasis were identified who underwent CRS-HIPEC. Patients with ovarian metastasis more often had a primary appendiceal tumour and had a more extensive intra-abdominal tumour load compared to patients without ovarian metastases. Median follow-up time was 45 months (95% confidence interval (CI): 37-53 months). Overall survival (OS) did not differ significantly between the two groups with a median OS in the ovarian metastasis group of 40 months (95% CI 26-54) compared to 64 months (95% CI 17-111, P = 0.478) in the non-ovarian metastasis group. Recurrence patterns did not differ significantly between groups (p = 0.183). CONCLUSIONS: Patients with ovarian metastasis of colorectal and appendiceal origin who underwent CRS-HIPEC had similar outcome compared to patients without ovarian metastasis. Given the findings of high coincidence of peritoneal metastases with ovarian metastases and ovarian metastases not being an independent factor for survival after CRS-HIPEC, this procedure should be recommended for patients with peritoneal metastases and ovarian metastases of colorectal and appendiceal carcinoma.

Perioperative systemic chemotherapy in peritoneal carcinomatosis of lymph node positive colorectal cancer treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

BACKGROUND: Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) is the preferred treatment of peritoneal carcinomatosis (PC) of colorectal carcinoma. Patients with positive lymph node status have worse survival after CRS-HIPEC, which is probably due to higher rates of systemic failure. In this study, we analysed the effect of administration and timing of systemic chemotherapy on the outcome of lymph node positive colorectal carcinoma patients treated with CRS-HIPEC. PATIENTS AND METHODS: A prospective database was reviewed to identify lymph node positive patients with PC treated with CRS-HIPEC within 1 year after primary tumour diagnosis between 2004 and 2012. Medical history of the patients was studied for the administration of perioperative systemic chemotherapy and follow-up. Outcome parameters were progression-free survival (PFS), overall survival (OS) and pattern of recurrence. RESULTS: Seventy-three patients treated with CRS-HIPEC for PC from lymph node positive colorectal carcinoma were identified. Fourteen patients received pre-CRS-HIPEC chemotherapy only, 32 patients underwent post-CRS-HIPEC chemotherapy only, 9 patients received chemotherapy both pre- and post-CRS-HIPEC and 16 patients did not receive any systemic chemotherapy. Of the 47 patients who did not receive pre-CRS-HIPEC chemotherapy, 11 (23%) did not receive any chemotherapy due to major postoperative complications. PFS and OS were significantly higher in patients who received systemic chemotherapy (PFS: median 15 versus 4 months, P = 0.024; OS: median 30 versus 14 months, P = 0.015), although this difference was attenuated after adjustment for major complications. Different chemotherapy timings did not differ significantly in either survival or recurrence patterns. CONCLUSIONS: In patients with PC from lymph node positive colorectal carcinoma, perioperative systemic chemotherapy is associated with increased OS and PFS, although this difference may be partly explained by the occurrence of major postoperative complication; with no evidence of difference in PFS, OS and systemic recurrence rate by timing of systemic chemotherapy.