Preoperative chemoradiotherapy does not compromise the feasibility of adjuvant chemotherapy for patients with pancreatic ductal adenocarcinoma

The effect of preoperative chemotherapy and chemoradiotherapy on pancreatic fistula and other surgical complications after pancreatic resection: a systematic review and meta-analysis of comparative studies

BACKGROUND

Preoperative chemo- or chemoradiotherapy is recommended for borderline-resectable pancreatic cancer. The aim of this study was to determine the impact of preoperative therapy on surgical complications in patients with resected pancreatic cancer.

METHODS

This systematic review and meta-analysis included studies reporting on the rate of surgical complications after preoperative chemo- or chemoradiotherapy versus immediate surgery in pancreatic cancer patients. The primary endpoint was the rate of grade B/C POPF. Pooled odds ratios were calculated using random-effects models.

RESULTS

Forty-one comparative studies including 25,389 patients were included. Vascular resections were more often performed after preoperative therapy (29.4% vs. 15.7%, p < 0.001). Preoperative therapy was associated with a lower rate of grade B/C POPF as compared to immediate surgery (pooled OR 0.47, 95%CI 0.38-0.58). This reduction was mostly obtained by preoperative chemoradiotherapy (OR 0.46, 95%CI 0.29-0.73), but not by preoperative chemotherapy alone (OR 0.83, 95%CI 0.59-1.16). No difference was demonstrated for major morbidity, mortality, postpancreatectomy haemorrhage, delayed gastric emptying and overall morbidity.

CONCLUSION

Preoperative chemo- and chemoradiotherapy in patients with pancreatic cancer appears to be safe with respect to POPF and other surgical complications as compared to immediate surgery. The reduced rate of POPF appears to be attributable to preoperative chemoradiation.

Randomized phase II study of gemcitabine and S-1 combination therapy versus gemcitabine and nanoparticle albumin-bound paclitaxel combination therapy as neoadjuvant chemotherapy for resectable/borderline resectable pancreatic ductal adenocarcinoma (PDAC-GS/GA-rP2, CSGO-HBP-015)

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease, and multimodal strategies, such as surgery plus neoadjuvant chemotherapy (NAC)/adjuvant chemotherapy, have been attempted to improve survival in patients with localized PDAC. To date, there is one prospective study providing evidence for the superiority of a neoadjuvant strategy over upfront surgery for localized PDAC. However, which NAC regimen is optimal remains unclear.

METHODS

A randomized, exploratory trial is performed to examine the clinical benefits of two chemotherapy regimens, gemcitabine plus S-1 (GS) and gemcitabine plus nab-paclitaxel (GA), as NAC for patients with planned PDAC resection. Patients are enrolled after the diagnosis of resectable or borderline resectable PDAC. They are randomly assigned to either NAC regimen. Adjuvant chemotherapy after curative resection is highly recommended for 6 months in both arms. The primary endpoint is tumor progression-free survival time, and secondary endpoints include the rate of curative resection, the completion rate of protocol therapy, the recurrence type, the overall survival time, and safety. The target sample size is set as at least 100.

DISCUSSION

This study is the first randomized phase II study comparing GS combination therapy with GA combination therapy as NAC for localized pancreatic cancer.

TRIAL REGISTRATION

UMIN Clinical Trials Registry UMIN000021484 . This trial began in April 2016.

[Predictors of external pancreatic fistulae after pancreatic resection]

Despite a significant decrease in postoperative mortality after pancreatic resections in recent years (5.2-15% after pancreatoduodenectomy and about 5% after distal pancreatectomy), incidence of postoperative complications remains high (30-50% and 22-50%, respectively). Postoperative pancreatic fistula is one of the most common and formidable complications. Currently, most authors use the classification proposed by the International Study Group for Pancreatic Fistula (biochemical failure, fistula type B and C). Prediction of the risk of postoperative fistula is still a complex and unresolved problem of modern surgical pancreatology. According to the literature, the main risk factors of postoperative pancreatic fistulae are obesity and high body mass index, concomitant cardiovascular diseases, no neoadjuvant chemo- and radiotherapy, soft pancreatic texture, narrow pancreatic duct, no fibrotic changes in parenchyma, adipose infiltration of the pancreas, advanced intraoperative blood loss, as well as center experience. Most often, magnetic resonance imaging, computed tomography, ultrasound elastography and various multivariate risk assessment systems are used to estimate the risk of pancreatic fistulae. However, a generally accepted technique does not exist. This manuscript is devoted to analysis of risk factors of postoperative pancreatic fistulae and diagnostic methods for assessment of this risk.

Application of C. elegans cancer screening test for the detection of pancreatic tumor in genetically engineered mice

Pancreatic ductal adenocarcinoma (PDAC) exhibits a very early onset of metastasis. Thus, early detection and treatment are pivotal to successful eradication of pancreatic cancers. Economical and non-invasive cancer screening systems is indispensable for this purpose. Previously our group developed a novel method to detect various kinds of human cancer using nematode Caenorhabditis elegans (C. elegans) that respond to cancer odor in urine; however, whether this method is useful for non-human species remains to be understood. In this study, we examined its effectiveness in the detection of murine pancreatic tumor spontaneously generated in genetically-engineered mice. We generated pancreas-specific Kras ^G12D and/or c-Met deletion mutant mice and measured the probability of spontaneous tumor generation in these mice. The chemotactic indexes of C. elegans to the urine samples of these mutant mice were measured. As previously described, oncogenic Kras^G12D was necessary to induce pancreatic intraepithelial neoplasia in this mouse model, while c-Met mutation did not show further effect. The chemotactic analysis indicated that C. elegans avoids urine of healthy recipient mice, while they tended to be attracted to urine of mice with Kras^G12D . Our study demonstrated that C. elegans can recognize the odor of pancreatic cancer in urine of Kras^G12D model mouse, suggesting the similarity of cancer odor between species. Our result facilitates further studies on mechanism of cancer detection by C. elegans.

The investigation of the survival time after recurrence in patients with pancreatic ductal adenocarcinoma for individualization of adjuvant chemotherapy

PURPOSE

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease; however, the frequency of recurrence can be reduced if curative surgery following adjuvant chemotherapy is applied. At present, adjuvant chemotherapy is uniformly performed in all patients, as it is unclear which tumor types are controlled best or worst. We investigated patients with recurrence to establish the optimum treatment strategy.

METHODS

Of 138 patients who underwent curative surgery for PDAC, 85 developed recurrence. Comprehensive clinicopathological factors were investigated for their association with the survival time after recurrence (SAR).

RESULTS

The median SAR was 12.6 months. Treatments for recurrence included best supportive care, GEM-based therapy and S-1. The performance status [hazard ratio (HR) 0.12, P < 0.001], histological invasion of lymph vessels (HR 0.27, P < 0.001), kind of treatment for recurrence (HR 5.0, P < 0.001) and initial recurrence site (HR 2.9, P < 0.001) were independent significant risk factors for the SAR. The initial recurrence sites were the liver (n = 21, median SAR 8.8 months), lung (n = 10, 14.9 months), peritoneum (n = 6, 1.7 months), lymph nodes (n = 6, 14.7 months), local site (n = 17, 13.9 months) and multiple sites (n = 25, 10.1 months). A shorter recurrence-free survival (< 1 year) and higher postoperative CA19-9 level were significantly associated with critical recurrence (peritoneal/liver).

CONCLUSIONS

Several risk factors for SAR were detected in this study. Further investigations are needed to individualize the adjuvant chemotherapy for each patient with PDAC.

Association of iron metabolic enzyme hepcidin expression levels with the prognosis of patients with pancreatic cancer

Hepcidin and ferroportin, which are known as key iron regulators, may be used in future treatments of pancreatic ductal adenocarcinoma. Iron is essential for life support; it helps oxygen molecules bind to hemoglobin and acts as an important catalytic enzyme center. However, iron overload is a risk factor for cancer, possibly through the generation of reactive oxygen species (ROS). Hepcidin, which is a peptide hormone mainly generated by the liver, inhibits iron absorption via enterocytes and iron release from macrophages. Notably, hepcidin regulates iron homeostasis in the body by regulating the iron transporter ferroportin. In the present study, it was assumed that high hepcidin expression and low ferroportin expression result in malignancy. Therefore, it was examined whether hepcidin and ferroportin expression levels were correlated with the prognosis of pancreatic cancer in patients. Results revealed that high hepcidin expression levels and low ferroportin expression levels in pancreatic cancer tissue were significantly associated with poor prognosis in the analyses of overall survival (P=0.0140 and 0.0478, respectively). Additionally, there was no significant difference in disease-free survival in the hepcidin- and ferroportin-staining groups. Hepcidin expression correlated with the pathological stage and vascular invasion (P=0.0493 and 0.0400, respectively), and ferroportin expression was correlated with age (P=0.0372). Multivariate analysis of overall survival in the hepcidin-staining group revealed that pathological N factor (pN), adjuvant chemotherapy, and hepcidin expression were independent prognostic factors (P=0.0450, 0.0002, and 0.0049, respectively). Similarly, multivariate analysis of overall survival in the ferroportin-staining group revealed that vascular invasion, and ferroportin expression were independent prognostic factors (P=0.0028, P<0.0001, and P=0.0056, respectively). Thus, hepcidin and ferroportin expressions might be novel prognostic indicators for pancreatic cancer.

Preoperative imaging evaluation of pancreatic pathologies for the objective prediction of pancreatic fistula after pancreaticoduodenectomy

In performing pancreaticoduodenectomy (PD) or when conducting clinical trials involving PD procedure, a universal platform for predicting the risk of postoperative pancreatic fistula (POPF) is indispensable. In this article, the most significant imaging studies that focused on the objective preoperative assessment of pancreatic pathologies in association with the occurrence of POPF after PD were reviewed. Several recently developed imaging modalities can objectively predict the occurrence of POPF after PD by assessing the elasticity, fibrosis, and fatty infiltration of the pancreas. These valuable imaging modalities include: (1) acoustic radiation force impulse ultrasound (US) electrography which provides information about the elastic properties of the pancreas; (2) contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) with/without contrast-enhancement which reflect the histological degree of pancreatic fibrosis; and (3) multi-detector row CT and/or MRI which reflects the microscopic fatty infiltration of the pancreas. The precise and objective preoperative risk assessment of POPF enables surgeons to customize appropriate management strategies for individual patients undergoing PD. This would be also beneficial for stratifying patients for enrolment in relevant studies that involve pancreatic head resection, as objective criteria could be set for the definitive evaluation of collected data related to surgical outcomes across different institutions and surgeons.

Patients Treated with Preoperative Chemoradiation for Pancreatic Ductal Adenocarcinoma have Impaired Bone Density, a Predictor of Distant Metastasis

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a lethal neoplasm that spreads to surrounding tissue or distant sites. This study investigated distant metastases in PDAC patients with or without preoperative chemoradiation therapy (CRT), focusing on vitamin D levels and bone density.

METHODS

This study included 146 patients with PDAC who underwent surgery from 2007 to 2014. Bone density was evaluated using computed tomography, and the preoperative vitamin D level was calculated by enzyme-linked immunosorbent assay (ELISA) for patients with available plasma (48 cases).

RESULTS

When the patients were divided into two groups according to the change in bone density, the group with decreased bone density had a shorter distant metastasis-free survival time (DMFS) after surgery than the other group (p < 0.05). Low vitamin D was a weak predictor of DMFS, but the difference was not significant (p = 0.08), perhaps because of the sample size. Multivariate analysis indicated three significant factors associated with distant metastasis: a decrease in bone density (hazard ratio [HR], 2.17; p = 0.04), normalization of the Dupan-2 value after surgery (hazard ratio [HR], 0.39; p = 0.02), and completion of adjuvant chemotherapy (HR, 0.29; p < 0.01). Univariate analysis showed that a low vitamin D concentration (<20 pg/ml) was a risk factor (p = 0.04) for bone density change. Multivariate analysis found that preoperative CRT was the only factor associated (±, OR, 5.8; p = 0.04) with bone density change, suggesting that preoperative CRT significantly decreases bone density in patients with insufficient vitamin D.

CONCLUSION

Patients treated with preoperative CRT tend to have impaired bone density, which is a predictor of distant metastasis. Thus, vitamin D supplementation may decrease distant metastasis.

Effectiveness and risk of biliary drainage prior to pancreatoduodenectomy: review of current status

Preoperative biliary drainage (PBD) prior to pancreatoduodenectomy (PD) has gained popularity as bridge management to resolve jaundice, but its role is being challenged as it is thought to increase morbidity. To clarify the current recommendations for PBD prior to PD, we reviewed the literature, including all relevant articles published in English up until December, 2015. There is increasing evidence that PBD causes bile infection, which is related to the morbidity of infectious complications. Results of transhepatic drainage are poorer than those of endoscopic stenting, especially in an oncologic setting, although it is still unclear whether metallic stents are superior to nasobiliary drainage. PBD should be avoided whenever possible and performed only in selected cases, such as the emergency setting, an inevitable long delay (>4 weeks) before PD, and jaundice-related anorexia. Seemingly, transhepatic drainage should be reserved for refractory cases if endoscopic drainage is not possible. Further studies comparing endoscopic drainage techniques, such as metallic stents and nasobiliary drainage, are required to assess the most effective technique of PBD. Bile infection should be prevented by adequate antibiotic prophylaxis and treated even in the absence of symptoms, and bile status should be assessed systematically.

Expression of podoplanin in stromal fibroblasts plays a pivotal role in the prognosis of patients with pancreatic cancer

Purpose

To investigate the role of podoplanin (PDPN) expression in invasive ductal carcinoma of the pancreas (IDCP) in humans.

Methods

Tumor samples were obtained from 95 patients with IDCP. Immunohistochemical staining was done to evaluate the expression of PDPN in cancer tissues.

Results

PDPN was detected predominantly in stromal fibroblasts, stained with α-smooth muscle actin. The cutoff value of PDPN-positive areas was calculated according to a histogram. There was no significant difference in clinicopathologic factors between patients with high vs. those with low PDPN expression. The high PDPN group showed significantly poorer disease-free and disease-specific survival rates than the low PDPN group. Among patients from the high PDPN group, those with lymph node metastases and those with a tumor larger than 20 cm in diameter had significantly poorer prognoses than similar patients from the low PDPN group. Multivariate Cox proportional hazards analysis indicated that a high expression of PDPN was an independent risk factor for disease-specific survival.

Conclusions

PDPN expression in cancer-related fibrotic tissues is associated with a poor prognosis, especially in patients with large tumors or lymph node metastases.

Successful removal of an internal pancreatic stent that migrated into the bile duct using double-balloon enteroscopy after pancreaticoduodenectomy

PURPOSE

Internal stents used during pancreaticoduodenectomy (PD) are generally spontaneously passed through the rectum by defecation. However, we encountered six patients with internal stents that migrated into the bile duct after PD. We herein report the outcomes of these six patients and the usefulness of double-balloon enteroscopy (DBE) for removal of such stents from the bile duct.

METHODS

An internal stent was placed across pancreaticojejunostomy in 416 (68.8%) of 605 consecutive patients undergoing PD between 2005 and 2015. This study evaluated the characteristics and outcomes of the six patients whose internal stent migrated into the bile duct.

RESULTS

Migration of an internal stent into the bile duct was found during follow-up computed tomography (CT) in 6 (1.4%) of 416 patients who had an internal stent placed during PD. Three patients developed stent-induced cholangitis, and two had bile duct stones. Excluding one patient whose internal stent spontaneously slipped out and disappeared from the bile duct, all patients underwent successful removal of a stent from the bile duct by a single instance of biliary intervention involving DBE.

CONCLUSIONS

Removal of a stent from the bile duct using DBE is a feasible and useful procedure that should be considered if an internal stent is detected during follow-up CT after PD.

Risk factors of postoperative pancreatic fistula after distal pancreatectomy using a triple-row stapler

PURPOSE

Postoperative pancreatic fistula (POPF) is one of the major complications in patients who undergo distal pancreatectomy (DP). Recently, dividing the pancreas by stapler is a commonly performed technique, however, POPF still occurs. Therefore, the purpose of this study was to investigate the risk factors for POPF after DP using a triple-row stapler.

METHODS

A total of 75 patients underwent DP using a triple-row stapler (Endo GIA™ Reloads with Tri-Staple™ Technology 60 mm; COVIDIEN, North Haven, CT, USA) at Yamanashi University from December 2012 to December 2016. The clinical risk factors for POPF after DP using a triple-row stapler were identified based on univariate and multivariate analyses.

RESULTS

Clinical POPF (ISGPF Grade B and C) was seen in 7 of 75 patients (9.3%). The body mass index (BMI) was significantly higher in the patients with POPF (26.8 ± 0.5 kg/m²) compared with the patients without POPF (21.4 ± 0.4 kg/m²; a cut-off value; 25.7 kg/m²). In addition, the patients with POPF were significantly younger than the patients without POPF (56.4 ± 5.6 vs 67.0 ± 1.5; a cut-off value was 57.0 years old).

CONCLUSIONS

BMI and age were found to be significant risk factors for POPF after DP using a triple-row stapler.

The basal nutritional state of PDAC patients is the dominant factor for completing adjuvant chemotherapy

PURPOSE

Pancreatic ductal adenocarcinoma (PDAC) is highly lethal, and several clinical trials have shown that adjuvant chemotherapy after curative resection can improve the prognosis of these patients. However, the adjuvant chemotherapy completion rate is less than satisfactory. If this rate could be increased then the overall prognosis of PDAC might be improved; however, reports addressing this problem are insufficient. To elucidate the factors, we retrospectively investigated PDAC patients.

METHODS

Various factors of 121 PDAC patients undergoing R0 resection, including preoperatively treated patients, were investigated. Univariate and multivariate analyses were performed to investigate the factors that were associated with the completion of adjuvant chemotherapy.

RESULTS

The analysis identified age and the prognostic nutritional index (PNI) as significant independent factors. A receiver operating characteristic curve analysis of age yielded a cutoff value of 67 years (sensitivity, 64%; specificity, 78%). Univariate and multivariate analyses of the 61 patients who were over 67 years of age revealed that the PNI (odds ratio, 0.85; P = 0.048) and Evans grade (odds ratio, 0.041; P = 0.0010) were significant factors for the completion of chemotherapy.

CONCLUSIONS

The results of our investigation suggest that nutrition should be controlled in older PDAC patients to facilitate the completion of adjuvant chemotherapy.

Novel intraoperative use of the "Tensipresser" to assess factors predictive of pancreatic fistula after pancreaticoduodenectomy

PURPOSES

Pancreatic fistula (PF) is a challenging complication of pancreaticoduodenectomy (PD). 'Soft pancreas' is reported as a risk factor for PF; however, palpation by the surgeon is not an objective method of evaluating pancreatic texture. We conducted this study to investigate whether a texture analyzer called a "Tensipresser" can be used to quantify pancreatic tissue hardness and predict the development of postoperative PF.

METHODS

We assessed pancreatic texture in 85 patients who underwent PD. After surgeons assessed the texture of the pancreas subjectively, the physical properties were measured on the pancreatic margin intraoperatively, by the two-bite method using the "Tensipresser". The incidence and severity of PF were based on the definitions of the International Study Group on Pancreatic Fistula.

RESULTS

Symptomatic PF (grade B and C) developed in 16% of the patients. Patients were divided into two groups based on the Tensipresser measurement: those with a soft and fragile pancreas with hardness < 2070 gw/cm² and cohesiveness < 0.65 (SF group); and all other patients (non-SF group). In the univariate and multivariate analysis, a small pancreatic duct diameter (<4 mm), no conduction of preoperative chemoradiation therapy, and inclusion in the SF group were significant predictors of PF.

CONCLUSION

The Tensipresser can evaluate pancreatic texture objectively, helping to define intraoperatively, those at risk of the development of PF.

Epidemiology and risk factors associated with surgical site infection after different types of hepatobiliary and pancreatic surgery

PURPOSE

Surgical site infection (SSI) is one of the most common healthcare-associated infections (HAIs); however, SSI after hepatobiliary and pancreatic surgery (HBPS) has not been well investigated in a large cohort of patients. This study analyzed the factors associated with SSI following HBPS in Japan, using a Japanese national database.

METHODS

Data on HBPS performed between 2012 and 2014 were extracted from a national monitoring system for HAI: The Japan Nosocomial Infections Surveillance. Using multivariate logistic regression, I assessed the factors associated with SSI.

RESULTS

The cumulative incidence of SSI following HBPS was 15.6% (2873/18,398). The incidence of SSI after pancreatoduodenectomy was 28.0%, which was significantly higher than that after liver resection and other types of HBPS (8.8 and 15.5%, respectively). Among the four traditional risk factors, the American Society of Anesthesiologists score was ineffective for predicting SSI in the final model of all three types of surgery. Additional risk factors were identified, including age and male gender.

CONCLUSIONS

The incidence of and factors associated with SSI after the three types of HBPS analyzed differed significantly. To accurately compare hospital performance in relation to SSI following HBPS, the operative procedure category in the surveillance system must be divided into three types.

A novel preoperative predictor of pancreatic fistula using computed tomography after distal pancreatectomy with staple closure

PURPOSE

A thick pancreas has proven to be a conspicuous predictor of pancreatic fistula (PF) following distal pancreatectomy (DP) using staples. Other predictors for this serious surgical complication currently remain obscure. This study sought to identify novel predictors of PF following DP.

METHODS

One hundred and twenty-two patients were retrospectively assessed to determine the correlation between PF occurrence and the clinicopathological findings and radiologic data from preoperative computed tomography (CT). CT assessments included the thickness of the pancreas (TP) and pancreatic CT number (pancreatic index; PI), calculated by dividing the pancreatic CT by the splenic CT density.

RESULTS

Twenty-four patients (19.7%) developed a clinically relevant PF. TP was identified as an independent risk factor for PF in multivariate analyses (odds ratio 1.17; P = 0.0095). In subgroup analyses, a lower PI in a thick pancreas was a significant predictor of PF (P = 0.032). The combination of these two prediction parameters, known as the TP-to-PI ratio (TPIR), showed a significantly better prediction ability than TP alone (area under the receiver operating characteristic curve for the incidence of PF, TPIR 0.80 vs. TP 0.69; P = 0.037).

CONCLUSION

Combining the CT number with TP substantially improves the prediction ability for the incidence of PF following DP with staple use.

Cells of origin of pancreatic neoplasms

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignant disease associated with poor prognosis, despite recent medical advances. It is of great importance to understand the initial events and cells of origin of pancreatic cancer to prevent the development and progression of PDAC. There are three distinct precursor lesions that develop into PDAC: pancreatic intraepithelial neoplasms (PanINs), intraductal papillary mucinous neoplasms (IPMNs), and mucinous cystic neoplasms (MCNs). Studies on genetically engineered mouse models have revealed that the initiation and development of these lesions largely depend on genetic alterations. These lesions originate from different populations in the pancreas. PanIN development seems to be the result of the transdifferentiation of acinar cells, whereas IPMNs most likely arise from the progenitor niche of the pancreatic ductal epithelium. Pancreatic carcinogenesis is dependent on various events, including gene alterations, environmental insults, and cell types. However, further studies are needed to fully understand the initial processes of pancreatic cancer.

Fatty Acid-Mediated Stromal Reprogramming of Pancreatic Stellate Cells Induces Inflammation and Fibrosis That Fuels Pancreatic Cancer

OBJECTIVES

Pancreatic ductal adenocarcinoma is one of the deadliest diseases worldwide. Fatty acids (FAs) have properties that affect both cancer cells and tumor environment. We assessed the effects of FAs on malignant characteristics in a pancreatic cancer and pancreatic stellate cell (PSC) coculture model. This study aimed to clarify the FA signature of PSC-derived inflammation and fibrosis in vitro and in a clinicopathological analysis.

METHODS

The in vitro model involved coculture of the human pancreatic cancer cell lines PANC-1 and MIA PaCa-2 with human PSCs. Clinical histological samples were analyzed to characterize the surgical margins of samples from patients who received distal pancreatectomies.

RESULTS

The pancreatic cancer cells took up lipids from the culture media. Saturated and unsaturated FAs were required to induce inflammatory responses in human PSCs, and the cocultures showed fibrotic changes. Clinical samples from pancreatic ductal adenocarcinoma patients had more fatty and fibrotic changes in the normal tissue in the surgical margins than samples from noncancer patients.

CONCLUSIONS

Inflammation and fibrosis levels were increased in pancreatic cancer specimens, supporting the in vitro observations and suggesting that PSCs contribute to pancreatic carcinogenesis. Pancreatic stellate cells thus represent a potential therapeutic target for suppressing stromal changes in pancreatic cancer.

The impact of margin status determined by the one-millimeter rule on tumor recurrence and survival following pancreaticoduodenectomy for pancreatic ductal adenocarcinoma

PURPOSE

The tumor-node-metastasis (TNM) classification defines R1 as the presence of tumor cells at the resection margin, while the current Royal College of Pathologists guidelines for pancreaticoduodenectomy specimens regard the presence of tumor cells within 1 mm from the resection margin as R1 (the "1-mm rule"). The aims of this study were to investigate the resection margin status of pancreatic head cancer retrospectively according to both the TNM and 1-mm rule classifications, and to evaluate the postoperative survival and tumor recurrence patterns.

METHODS

A total of 117 patients with pancreatic head cancer were the subjects of this study.

RESULTS

R1^{1-mm rule} resection was associated with a significantly worse disease-free survival (DFS) than R0^{1-mm rule} resection (p = 0.0259), while R1^TNM had no impact on DFS. R1^{1-mm rule} resection margin status correlated with the incidence of tumor recurrence in the liver (p = 0.0483). In a multivariate analysis, R1^{1-mm rule} resection was the independent variable for predicting poor DFS (hazard ratio 1.71; p = 0.0289).

CONCLUSIONS

R1 resection margin status determined by the 1-mm rule may be an independent indicator for predicting disease recurrence, especially liver metastasis. These results may be useful for selecting the appropriate adjuvant therapy protocol and conducting strict surveillance in PDAC patients.