Michael Gubanski

Advances in the treatment of patients with gastric adenocarcinoma

Despite a decline in its incidence in the Western world, gastric cancer (GC) remains the fourth most frequent cancer diagnosis worldwide and is, after lung cancer, the second leading cause of death from a malignant disease globally. Based on the published literature, treatment guidelines and reports from international meetings, we here review the current treatment options for GC and discuss insights and perspectives from the latest clinical studies. The management of GC in the early stages of the disease is based on an optimal surgical resection of the primary tumor and the regional lymph nodes. However, less than one third of patients have a resectable disease at diagnosis and among those operated, more than half are not cured by surgery alone, due to a high rate of relapse. Thus, for the majority of patients, systemic cytotoxic therapy, and sometimes radiotherapy, is a treatment option both as an adjunct to surgery and in the palliative setting. Adjuvant chemotherapy offers only a marginal benefit and has not become a standard of care in the West. In North America, adjuvant chemoradiation is broadly used, shown to significantly improve overall survival, albeit with the cost of high toxicity. Furthermore, a recently reported study from the United Kingdom demonstrated a significant disease-free and survival benefit by the use of perioperative combination chemotherapy. Several chemotherapeutic agents have been tested as a palliative therapy in advanced GC including 5- fluorouracil (5-FU), oral pyrimidines, platinum derivatives, anthracyclines, taxanes and camptothecans. It is now accepted that chemotherapy is better than best supportive care only and that 5-FU based combinations are more effective than monotherapy. However, the response rates have generally been moderate and there is no consensus on the optimal combination of cytotoxic agents and the potential role of more recently developed “targeted therapies”.

Randomized phase II study of sequential docetaxel and irinotecan with 5-fluorouracil/folinic acid (leucovorin) in patients with advanced gastric cancer: the GATAC trial

BackgroundThe optimal chemotherapy in patients with advanced gastric carcinoma (GC) is yet to be determined. We compared sequential administration of docetaxel and irinotecan, both in combination with infused 5-fluorouracil/leucovorin (5-Fu/Lv), and randomly assigned patients to start with either of the two.MethodsPatients with previously untreated locally advanced or metastatic GC and with measurable lesions (response evaluation criteria in solid tumors; RECIST) were randomly assigned to start with docetaxel 45 mg/m2 (arm T) or irinotecan 180 mg/m2 (arm C) with bolus/44-h infusion of 5-Fu/Lv (day 1 every 2 weeks). After four courses, there was a prescheduled crossover to the alternative regimen for four additional courses.ResultsEighty-one patients were randomized and 78 started treatment. Complete and partial responses were seen in 31 (40%) patients after 8 weeks and in 32 (41%) after 16 weeks, with similar results in both study arms. The median overall survival (OS) was 11.5 and 10.6 months in arms T and C, respectively (P = 0.3). The two schedules were feasible and did not differ in the overall rate of severe adverse events (SAEs).ConclusionThis is the first randomized comparison of two of the newer cytostatic drugs in GC therapy. No differences favoring either arm T or arm C were found with respect to response rate, OS, or toxicity. The median OS of 11 months indicates that sequential administration of the two combinations is effective and is similar to triple combinations. Thus, comparable efficacy to platinum combinations appears to be obtained with newer, less toxic regimens when given sequentially.

Capecitabine as third line therapy in patients with advanced colorectal cancer

This study sought to determine whether third line therapy with capecitabine (cap.) could provide any clinical benefit in patients with advanced colorectal cancer who have progressed on 5-Fu combination therapy with both irinotecan and oxaliplatin. Twenty patients who were pretreated with and had progressed on irinotecan+Nordic FLv (5-Fu/leukovorin) and oxaliplatin+c.i. 5-Fu/leukovorin were studied. Cap. was administered at 1000–1250 mg/m2 bid d1-14 q 3 w. Time to progression (TTP) (either radiological or clinical) and overall survival (OS) were estimated with the Kaplan-Meier actuarial method. The median number of administered cap. courses was four. No radiological or biochemical responses were observed. Three patients were classified as having stable disease at three months. Two of these patients had, however, minor radiological progression and a ≥100% increase in CEA compared to base line. Seventeen patients were classified as having progressive disease during the first three months period. Median TTP and OS were 2.8 months and 6.1 months, respectively. A response rate of ≥15% for third line cap. in metastatic CRC can be ruled out. Median PFS was limited in the study population. This observation and the few cases with SD at three months, lead us to believe that little or no clinical benefit can be expected from single drug cap. in patients with irinotecan- and oxaliplatin-combination resistant advanced colorectal cancer.

Efficacy of pegylated liposomal doxorubicin in patients with advanced hepatocellular carcinoma

Presently, no effective systemic therapy is available for patients with advanced hepatocellular carcinoma (aHCC). We sought to determine whether systemic treatment with pegylated liposomal doxorubicin (PLD) would yield a response rate of 20% in chemotherapy naïve patients with aHCC. The study was designed according to the phase II Gehan two-step procedure with a precision of 10%. Enrolment criteria included histological diagnosis and radiological documentation of unresectable/metastatic HCC, WHO PS 0–2, relatively normal organ function, life expectancy greater than three months, lack of cardiomyopathy and active cardiac disease NYHA ≥II. PLD (40 mg/m2 IV 1h-infusion) was administered on d1 q 4 wk and response to treatment was evaluated radiologically every 3rd cycle (WHO-criteria). Secondary endpoints included overall (OS) and progression free survival (PFS) and registration of toxicity. The median number of administered PLD cycles was 3. The best radiological response among the first 14 patients was 1 PR, 5 SD, 3 PD, and 6 NE due to progressive disease clinically (Step 1). The 15th patient did not respond to the PLD-therapy and the study was closed for accrual as the pre-planned analysis could be executed (Step 2). A response rate ≥20% could be ruled out. The median PFS and OS survival was 82 days and 130 days, respectively. Adverse events were generally mild in the subgroup of patients without signs of moderate hepatic failure at base line. Patients with WHO PS 2, liver tumour involvement >50%, bilirubin ≥34 µmol/L, albumin <33 g/L, and/or Child Pugh B were unlikely to survive >90 days. PLD can be delivered safely in patients with aHCC and no signs of moderate hepatic failure. The therapy resulted, however, in few responses or cases of disease stabilization and has thus very limited activity in aHCC. Future studies on systemic chemotherapy should focus on patients without moderate hepatic failure, with WHO PS <2, and with liver tumour involvement <50%.

Dosimetric Comparison of Plans for Photon- or Proton-Beam Based Radiosurgery of Liver Metastases

Purpose Radiosurgery treatment of liver metastases with photon beams has been an established method for more than a decade. One method commonly used is the stereotactic body radiation therapy (SBRT) technique. The aim of this study was to investigate the potential sparing of the organs at risk (OARs) that the use of intensity-modulated proton therapy (IMPT), instead of SBRT, could enable. Patients and Methods A comparative treatment-planning study of photon-beam and proton-beam based liver-cancer radiosurgery was performed. Ten patients diagnosed with liver metastasis and previously treated with SBRT at the Karolinska University Hospital were included in the study. New IMPT plans were prepared for all patients, while the original plans were set as reference plans. The IMPT planning was performed with the objective of achieving the same target dose coverage as with the SBRT plans. Pairwise dosimetric comparisons of the treatment plans were then performed for the OARs. A 2-sided Wilcoxon signed-rank test with significance level of 5% was carried out. Results Improved sparing of the OARs was made possible with the IMPT plans. There was a significant decrease of the mean doses delivered to the following risk organs: the nontargeted part of the liver (P = .002), the esophagus (P = .002), the right kidney (P = .008), the spinal cord (P = .004), and the lungs (P = .002). The volume of the liver receiving less than 15 Gy was significantly increased with the IMPT plans (P = .004). Conclusion The IMPT-based radiosurgery plans provided similar target coverage and significant dose reductions for the OARs compared with the photon-beam based SBRT plans. Further studies including detailed information about varying tissue heterogeneities in the beam path, due to organ motion, are required to evaluate more accurately whether IMPT is preferable for the radiosurgical treatment of liver metastases.

Comparative study of the calculated risk of radiation-induced cancer after photon- and proton-beam based radiosurgery of liver metastases

INTRODUCTION The potential of proton therapy to improve the sparing of the healthy tissue has been demonstrated in several studies. However, even small doses delivered to the organs at risk (OAR) may induce long-term detriments after radiotherapy. In this study, we investigated the possibility to reduce the risk of radiation-induced secondary cancers with intensity modulated proton therapy (IMPT), when used for radiosurgery of liver metastases. MATERIAL AND METHODS Ten patients, previously treated for liver metastases with photon-beam based stereotactic body radiation therapy (SBRT) were retrospectively planned for radiosurgery with IMPT. A treatment plan comparison was then performed in terms of calculated risk of radiation-induced secondary cancer. The risks were estimated using two distinct models (Dasu et al., 2005; Schneider et al., 2005, 2009). The plans were compared pairwise with a two-sided Wilcoxon signed-rank test with a significance level of 0.05. RESULTS Reduced risks for induction of fatal and other types of cancers were estimated for the IMPT plans (p<0.05) with the Dasu et al. MODEL Using the Schneider et al. model, lower risks for carcinoma-induction with IMPT were estimated for the skin, lungs, healthy part of the liver, esophagus and the remaining part of the body (p<0.05). The risk of observing sarcomas in the bone was also reduced with IMPT (p<0.05). CONCLUSION The findings of this study indicate that the risks of radiation-induced secondary cancers after radiosurgery of liver metastases may be reduced, if IMPT is used instead of photon-beam based SBRT.

Comparison of gastric-cancer radiotherapy performed with volumetric modulated arc therapy or single-field uniform-dose proton therapy

Abstract Background: Proton-beam therapy of large abdominal cancers has been questioned due to the large variations in tissue density in the abdomen. The aim of this study was to evaluate the importance of these variations for the dose distributions produced in adjuvant radiotherapy of gastric cancer (GC), implemented with photon-based volumetric modulated arc therapy (VMAT) or with proton-beam single-field uniform-dose (SFUD) method. Material and methods: Eight GC patients were included in this study. For each patient, a VMAT- and an SFUD-plan were created. The prescription dose was 45 Gy (IsoE) given in 25 fractions. The plans were prepared on the original CT studies and the doses were thereafter recalculated on two modified CT studies (one with extra water filling and the other with expanded abdominal air-cavity volumes). Results: Compared to the original VMAT plans, the SFUD plans resulted in reduced median values for the V18 of the left kidney (26%), the liver mean dose (14.8 Gy (IsoE)) and the maximum dose given to the spinal cord (26.6 Gy (IsoE)). However, the PTV coverage decreased when the SFUD plans were recalculated on CT sets with extra air- (86%) and water-filling (87%). The added water filling only led to minor dosimetric changes for the OARs, but the extra air caused significant increases of the median values of V18 for the right and left kidneys (10% and 12%, respectively) and of V10 for the liver (12%). The density changes influenced the dose distributions in the VMAT plans to a minor extent. Conclusions: SFUD was found to be superior to VMAT for the plans prepared on the original CT sets. However, SFUD was inferior to VMAT for the modified CT sets.

Prognostic factors affecting survival after whole brain radiotherapy in patients with brain metastasized lung cancer

Abstract Background: Whole-brain radiotherapy (WBRT) has been the standard of care for multiple NSCLC brain metastases but due to its toxicity and lack of survival benefit, its use in the palliative setting is being questioned. Patient and methods: This was a single institution cohort study including brain metastasized lung cancer patients who received WBRT at Karolinska University Hospital. Information about Recursive Partitioning Analysis (RPA) and Graded Prognostic Assessment (GPA) scores, demographics, histopathological results and received oncological therapy were collected. Predictors of overall survival (OS) from the time of received WBRT were identified by Cox regression analyses. OS between GPA and RPA classes were compared by pairwise log rank test. A subgroup OS analysis was performed stratified by RPA class. Results: The cohort consisted of 280 patients. RPA 1 and 2 classes had better OS compared to class 3, patients with GPA <1.5 points had better OS compared to GPA≥ 1.5 points and age >70 years was associated with worse OS (p< .0001 for all comparisons). In RPA class 2 subgroup analysis GPA ≥1.5 points, age ≤70 years and CNS surgery before salvage WBRT were independent positive prognostic factors. Conclusions: RPA class 3 patients should not receive WBRT, whereas RPA class 1 patients should receive WBRT if clinically indicated. RPA class 2 patients with age ≤70 years and GPA ≥1.5 points should be treated as RPA 1. WBRT should be omitted in RPA 2 patients with age >70. In RPA 2 patients with age ≤70 years and GPA <1.5 points WBRT could be a reasonable option.