Implementing DPYD*2A Genotyping in Clinical Practice: The Quebec, Canada, Experience

BACKGROUND

Fluoropyrimidines are used in chemotherapy combinations for multiple cancers. Deficient dihydropyrimidine dehydrogenase activity can lead to severe life-threatening toxicities. DPYD*2A polymorphism is one of the most studied variants. The study objective was to document the impact of implementing this test in routine clinical practice.

METHODS

We retrospectively performed chart reviews of all patients who tested positive for a heterozygous or homozygous DPYD*2A mutation in samples obtained from patients throughout the province of Quebec, Canada.

RESULTS

During a period of 17 months, 2,617 patients were tested: 25 patients tested positive. All were White. Twenty-four of the 25 patients were heterozygous (0.92%), and one was homozygous (0.038%). Data were available for 20 patients: 15 were tested upfront, whereas five were identified after severe toxicities. Of the five patients confirmed after toxicities, all had grade 4 cytopenias, 80% grade ≥3 mucositis, 20% grade 3 rash, and 20% grade 3 diarrhea. Eight patients identified with DPYD*2A mutation prior to treatment received fluoropyrimidine-based chemotherapy at reduced initial doses. The average fluoropyrimidine dose intensity during chemotherapy was 50%. No grade ≥3 toxicities were observed. DPYD*2A test results were available in an average of 6 days, causing no significant delays in treatment initiation.

CONCLUSION

Upfront genotyping before fluoropyrimidine-based treatment is feasible in clinical practice and can prevent severe toxicities and hospitalizations without delaying treatment initiation. The administration of chemotherapy at reduced doses appears to be safe in patients heterozygous for DPYD*2A.

IMPLICATIONS FOR PRACTICE

Fluoropyrimidines are part of chemotherapy combinations for multiple cancers. Deficient dihydropyrimidine dehydrogenase activity can lead to severe life-threatening toxicities. This retrospective analysis demonstrates that upfront genotyping of DPYD before fluoropyrimidine-based treatment is feasible in clinical practice and can prevent severe toxicities and hospitalizations without delaying treatment initiation. This approach was reported previously, but insufficient data concerning its application in real practice are available. This is likely the first reported experience of systematic DPYD genotyping all over Canada and North America as well.

Optimizing treatment sequencing of chemotherapy for patients with rectal cancer: The KIR randomized phase II trial

BACKGROUND

Randomized studies have shown low compliance to adjuvant chemotherapy in rectal cancer patients receiving preoperative chemotherapy and external beam radiation (CT/EBRT) with total mesorectal excision. We hypothesize that giving neoadjuvant CT before local treatment would improve CT compliance.

METHODS

Between 2010-2017, 180 patients were randomized (2:1) to either Arm A (AA) with FOLFOX x6 cycles prior to high dose rate brachytherapy (HDRBT) and surgery plus adjuvant FOLFOX x6 cycles, or Arm B (AB), with neoadjuvant HDRBT with surgery and adjuvant FOLFOX x12 cycles. The primary endpoint was CT compliance to ≥85% of full-dose CT for the first six cycles. Secondary endpoints were ypT0N0, five-year disease free survival (DFS), local control and overall survival (OS).

RESULTS

Patients were randomized to either AA (n = 120, median age (MA) 62 years) or AB (n = 60, MA 63 years). 175/180 patients completed HDRBT as planned (97.2%). In AA, two patients expired during CT; three patients post-randomization received short course EBRT because of progression under CT (n = 2, AA) or personal preference (n = 1, AB). ypT0N0 was 31% in AA and 28% in AB (p = 0.7). CT Compliance was 80% in AA and 53% in AB (p = 0.0002). Acute G3/G4 toxicity was 35.8% in AA and 27.6% in AB (p = 0.23). With a median follow-up of 48.5 months (IQR 33-72), the five-year DFS was 72.3% with AA and 68.3% with AB (p = 0.74), the five-year OS 83.8% for AA and 82.2% for AB (p = 0.53), and the five-year local recurrence was 6.3% for AA and 5.8% for AB (p = 0.71).

CONCLUSION

We confirmed improved compliance to neoadjuvant CT in this study. Although there is no statistical difference in ypT0N0 rate, local recurrence, and DFS between the two arms, a trend towards favourable oncological outcomes is observed.

Peritoneal carcinomatosis index predicts survival in colorectal patients undergoing HIPEC using oxaliplatin: a retrospective single-arm cohort study

Abstract

Background

Peritoneal carcinomatosis (PC) from colorectal cancer is associated with poor prognosis. Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) has improved survival for patients with colorectal peritoneal carcinomatosis. However, standardization of HIPEC protocols, including which chemotherapeutic agent to use, is lacking in the literature. Therefore, we sought to report survival outcomes from colorectal cancer patients undergoing CRS/oxaliplatin-based HIPEC at our institution over the last 10 years.

Methods

Colorectal PC patients treated with CRS/oxaliplatin-based HIPEC 2004–2015 were included. Demographic, clinical, and oncologic data were abstracted from the medical record. Overall (OS) and disease-free survival (DFS) were calculated using Kaplan–Meier analysis. Univariate/multivariate Cox regression analysis was done.

Results

Laparotomy was performed in 113 patients for colorectal PC; 91 completed a curative intent CRS/HIPEC. At 3 and 5 years, OS for the CRS/HIPEC cohort was 75% and 55%, and DFS was 50% and 25%, respectively. On multivariate analysis, incremental increases in peritoneal carcinomatosis index (PCI) were associated with worse OS (p = 0.0001) and DFS (p = 0.0001). Grade III/IV complications were also associated with worse OS.

Conclusions

A standardized regimen of CRS and oxaliplatin-based HIPEC for colorectal PC is effective with favorable OS and DFS and acceptable complication rates.

Implementing DPYD*2A genotyping in clinical practice, the Quebec experience

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Background: Fluoropyrimidines (FU) are part of chemotherapy combinations for multiple gastrointestinal cancers. Deficient dihydropyrimidine deshydrogenase (DPD) activity can lead to severe life-threatening toxicities in 3-5% of populations tested. The DPYD*2A polymorphism leading to deficient DPD activity is one of the most studied variants. Methods: We retrospectively performed chart reviews of all patients that tested positive for a heterozygous or homozygous DPYD*2A mutation in samples obtained from patients throughout the province of Quebec (Canada). The study objective was to document the impact of implementing this test in routine clinical practice, including the effects on treatment types, delays and toxicities. Results: 2,617 patients were tested by PCR for the presence of DPYD*2A in a period of 17 months: 25 patients tested positive. All were Caucasian. 24 of the 25 patients were heterozygous (0.92%) and one was homozygous (0.038%). A chart review was available for 20 patients: 15 were tested upfront while five were performed following severe toxicities on the first cycle of FU-based chemotherapy. Of the five patients identified following toxicities, all had grade 4 cytopenias, 80% grade ≥ 3 mucositis, 20% grade 3 rash and 20% grade 3 diarrhea, with an average of 15 days of hospitalisations due to febrile neutropenia. Seven of the 13 patients identified upfront received FU-based chemotherapy at reduced initial doses ranging from 25 to 50%. The average dose during the course of chemotherapy was 50% and two patients reached 100% dosage. No grade ≥ 3 toxicities were observed. DPYD*2A test results were available in an average of 6 days, causing no significant delays in treatment initiation according to 99% of queried physicians. Conclusions: Upfront genotyping before FU-based treatment is feasible in clinical practice. It may prevent severe toxicities and hospitalisations without delaying treatment initiation. The administration of chemotherapy at reduced doses appears to be safe in patients heterozygous for DPYD*2A.

Long term survival analysis after hyperthermic intraperitoneal chemotherapy with oxaliplatin as a treatment for appendiceal peritoneal carcinomatosis

BACKGROUND AND OBJECTIVES

Complete cytoreductive surgery (CRS) followed by hyperthermic intraperitoneal chemotherapy (HIPEC) have been proven to lengthen survival in appendiceal peritoneal carcinomatosis (PC-A). The aim of this study was to analyze survival results of this therapy in our institution over the last 10 years.

METHODS

Data was retrospectively reviewed and analyzed. Treatment consisted of CRS plus HIPEC with oxaliplatin. Ronnett's histologic classification was used (peritoneal mucinous carcinomatosis (PMCA), PMCA with intermediate features (PMCA-I) and disseminated peritoneal adenomucinosis (DPAM)). Overall survival (OS) and disease-free survival (DFS) estimates were calculated using Kaplan-Meier survival curves.

RESULTS

109 patients with PC-A underwent laparotomy with curative intent. Of those, 92 underwent CRS plus HIPEC. Median follow-up was 42 months. The 5 and 10-year OS rates for the HIPEC group were 82.2% and 76.5%. The 5 and 10-year OS estimates for DPAM and PMCA-I subgroups were 100% and 100%, 78.1% and 72.9%, respectively. For the PMCA subgroup, the 3 and 5-year OS were 61.4% and 40.1%, respectively. The 5 and 10-year DFS estimates were 71.9% and 42.7%.

CONCLUSION

CRS plus HIPEC with oxaliplatin represent an effective therapeutic approach for PC-A. Long term OS estimates for patients treated at our institution are encouraging.

Rationale for the administration of systemic 5-FU in combination with heated intraperitonal oxaliplatin

BACKGROUND

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) with oxaliplatin (OX) is the standard of care for selected patients with peritoneal carcinomatosis of colorectal origin. Because 5-FU is mandatory to improve efficacy of OX when used by systemic route, several teams now empirically combine intravenous (IV) 5-FU with HIPEC OX, but this practice has yet to be supported by preclinical data. Using a murine model, we studied the impact of IV 5-FU on peritoneal absorption of HIPEC OX.

METHODS

Under general anesthesia, 24 Sprague-Dawley rats were submitted to 4 different doses of IV 5-FU (0, 100, 400 and 800 mg/m²) and a fixed dose of HIPEC OX (460 mg/m²) perfused at 40 °C during 25 min. At 25 min, samples in different compartments were harvested (peritoneum, portal vein and systemic blood) and the concentrations of 5-FU and OX were measured by high performance liquid chromatography.

RESULTS

Peritoneal absorption of OX was significantly higher (17.0, 20.1, 34.9 and 38.1 nmol/g, p < 0.0001) with increasing doses of 5-FU (0, 100, 400 and 800 mg/m², respectively). Peritoneal absorption of OX reached a plateau between 400 and 800 mg/m² of IV 5-FU.

CONCLUSION

IV 5-FU enhances peritoneal absorption of HIPEC OX. The most efficient dose of IV 5-FU to be used in combination with HIPEC OX seems to be 400 mg/m².

Hepatocyte Transplantation in the Long Evans Cinnamon Rat Model of Wilson's Disease

Wilson's disease (WD), caused by a mutation in the P-type copper transporting ATPase (Atp7b) gene, results in excessive accumulation of copper in the liver. Long Evans Cinnamon rats (LEC) bear a mutation in the atp7b gene and share clinical characteristics of human WD. To explore hepatocyte transplantation (HT) as therapy for metabolic liver diseases, 8-week-old LEC rats (n = 12) were transplanted by intrasplenic injection of hepatocytes from donor Long Evans (LE) rats. Immunosuppression was maintained with intraperitoneal tacrolimus. The success of HT was monitored at 24 weeks of life. Serum aminotransferases and bilirubin peaked at 14–21 weeks in both HT rats and nontransplanted controls, but at 24 weeks, survival was 97% in LEC-HT versus 63% in controls. All transplanted rats showed restored biliary copper excretion and reduced liver iron concentration associated with increased ceruloplasmin oxidase activity. Liver tissue expressed atp7b mRNA (11.9 ± 13.6%) indicative of engraftment of normal cells in 7 of 12 HT rats, associated with a reduced liver copper concentration compared to untreated LEC rats. Periportal islets of normal appearing hepatocytes, recognized by atp7b antibody, were observed in transplanted livers while lobular host cells showed persistent pleomorphic changes and inflammatory infiltrates. In conclusion, transplantation of normal hepatocytes prevented fulminant hepatitis, reduces chronic inflammation, and improved 6-month survival in LEC rats. Engraftment of transplanted cells, which express atp7b mRNA, repopulated the recipient liver with normal functional capacity.

Factors Predictive of Re-excision After Oncoplastic Breast-conserving Surgery

BACKGROUND

Oncoplastic surgery (OPS) consists of breast-conserving surgery (BCS) that allows for oncologically safe breast conservation and breast remodeling, thus reducing postoperative deformities. The purpose of the present study was to identify factors determining the risk of re-excision and complications after OPS.

PATIENTS AND METHODS

A retrospective analysis was conducted on patients who underwent OPS between 2009 and 2013, regardless of whether neoadjuvant chemotherapy was administered. Clinical and pathological factors were evaluated. Recursive partitioning analysis (RPA) was used to build regression trees for the prediction of re-excision.

RESULTS

Amongst the 129 patients treated by OPS procedures, 30.3% required re-excision. Predictive factors for re-excision were: being overweight (p=0.02), the presence of microcalcifications on mammography (p=0.003), and tumor multifocality (p=0.03). The RPA identified five terminal nodes based on microcalcifications on mammography, being overweight and the presence of ductal carcinoma in situ. Another model included minimal invasive margins (p<0.001), being overweight (p=0.02) and the presence of microcalcifications (p=0.01) on mammography yielded a model with an area under the receiver operating characteristic curve of 0.875.

CONCLUSION

Microcalcifications, tumor multifocality and being overweight were the factors identified as predictors of re-excision after OPS. These factors can serve as decisional tools before surgery.

Quilting Sutures Reduces Seroma in Mastectomy

BACKGROUND

Drainage duration and seroma formation occurring after mastectomy with or without axillary surgery lengthens hospitalization and delays adjuvant treatment. The aim of the study was to evaluate the effect of quilting in the prevention of seroma after mastectomy for breast cancer.

PATIENTS AND METHODS

Eighty-two breast cancer patients about to undergo mastectomy with or without axillary surgery lymphadenectomy were enrolled in the study. We conducted an observational comparison between 41 patients in whom quilting with closed suction drainage was used and 41 patients in whom drainage only was used.

RESULTS

The mean drained volume was significantly lower in the quilting group compared with the control group on days 1 and 2 (day 1: 107.1 mL vs. 156.5 mL; P = .02; day 2: 108.4 mL vs. 162.8 mL; P = .01). The mean drainage period was shorter in the quilting group (4.6 vs. 5.3 days; P = .046). There were fewer needle aspirations for seroma in the padding group (n = 14, 34.1% vs. n = 24, 58.5%; P = .03).

CONCLUSION

The use of padding after mastectomy seems to reduce seroma formation, volume drained, and length of drainage time.

Atrial fibrillation after pulmonary transplantation: incidence, impact on mortality, treatment effectiveness, and risk factors

BACKGROUND

Atrial fibrillation (AF) is common after thoracic surgery. Limited data exist concerning the incidence of AF, its impact on mortality, the effectiveness of therapy, and the risk factors of AF after pulmonary transplantation.

METHODS AND RESULTS

We reviewed the medical files of 224 consecutive lung transplant recipients who underwent surgery over a 10-year period at a large Canadian center. We collected patient characteristics, in-hospital treatments, and outcomes. Time-to-event analysis was used to account for in-hospital follow-up and models generated to assess the impact of AF on mortality and independent risk factors of AF after transplantation. Postoperative AF occurred in 65 patients (29%). AF was more likely to occur with complications such as pneumonia, mediastinitis, and bronchial dehiscence and was not an independent risk factor of mortality (hazard ratio=1.56; 95% confidence interval, 0.52-4.63). Pharmacological or electric therapy for rhythm or rate control of AF was administered to 97% of patients. Intravenous amiodarone was used in 46%, electric cardioversion in 28%, and heparin in 26%. Only 1 patient remained in AF at discharge. Age (hazard ratio=1.08 by year; 95% confidence interval, 1.05-1.12), bilateral transplantation (hazard ratio=1.87; 95% confidence interval, 1.03-3.42), and a history of AF before the transplantation (hazard ratio=4.48; 95% confidence interval, 1.05-19.11) were found to be independently associated with an increased incidence of postoperative AF.

CONCLUSIONS

AF is fairly common after pulmonary transplantation, transient, and relatively benign. It is not independently associated with increased in-hospital mortality. Most patients return to sinus rhythm before discharge. Age, prior AF, and bilateral transplantation increase the risk of postoperative AF.