Radiotherapy for Liver Cancer: An International Multi-Centre Pooled Analysis of 925 Cases

PURPOSE/OBJECTIVE(S)

Primary and secondary liver cancer incidence is growing and has a poor prognosis. The standard use of radiation has been hampered by studies with a wide range of patients, different management protocols and varied outcomes. To overcome this heterogeneity in the literature, larger and higher-level trials are warranted, but, so far, have been difficult to implement. Therefore, pooled analyses may offer the best way to determine the benefit of radiation, identify treatment parameters needed to optimize treatment techniques, and identify patient factors that allow for better patient selection.

MATERIALS/METHODS

Patients with liver cancer treated by radiotherapy at centers in Canada, United States and Australia was pooled. Patient and treatment characteristics were noted, as well as the clinical outcomes of local control within 1 year, recurrence and mortality. Stepwise Cox proportional hazards models were used to identify significant predictors for recurrence and mortality. Patients were stratified by center, and primary versus metastatic disease.

RESULTS

A total of 925 patients were included in this study. Mean age was 67 years, and 45% had a primary diagnosis of hepatocellular carcinoma. 1-year local control rate was 80%. Median survival was 1.8 years (1.9 years for primary liver cancer, and 1.4 years for metastatic liver cancer). Higher total dose and BED was associated with better survival. Median time to recurrence was 1.5 years. Higher total dose was associated with lower risk of recurrence CONCLUSION: As one of the largest pooled analyses in hepatic cancer, this international multi-center study provides pragmatic data on clinical outcomes of patients receiving radiotherapy for liver cancer. This database may assist in better selection of patients for future studies and answer questions such as what is the optimal dose and which patients benefit from treatment.

TROG 15.03/ANZUP International Multicenter Phase II Trial of Focal Ablative STereotactic RAdiotherapy for Cancers of the Kidney (FASTRACK II)

PURPOSE/OBJECTIVE(S)

Stereotactic body radiotherapy (SBRT) is an emerging non-invasive alternative for primary renal cell cancer (RCC) in patients unsuitable for surgery. The objective of the FASTRACK II clinical trial was to investigate the efficacy of SBRT for primary RCC.

MATERIALS/METHODS

This non-randomized, intergroup multi-institutional phase II study was activated in 7 Australian centers and 1 Dutch center, through the Trans Tasman Radiation Oncology Group (TROG) and the Australian and New Zealand Urogenital and Prostate Cancer Trials Group (ANZUP). Eligible patients had biopsy confirmed diagnosis of primary RCC with a single lesion within a kidney, ECOG performance ≤2 and were medically inoperable, high risk or declined surgery. For tumors ≤4 cm a single fraction of 26 Gy was prescribed, for tumors > 4 cm, 42 Gy in three fractions was prescribed. The primary outcome of the study was to estimate the efficacy of SBRT for primary RCC, defined as local control based on RECIST criteria. The study was powered assuming that 1-year local control would be 90%, with the null hypothesis of ≤80% considered undesirable and not worthy of proceeding to a future randomized controlled trial.

RESULTS

Between July 2016 and February 2020, 70 patients were enrolled with a median follow-up of 42 months. Median age was 77 years. Forty-nine patients were male (70%), median BMI was 32 and median Charlson comorbidity score was 7. The median [IQR] RENAL complexity score was 8 [7-10]. Biopsy confirmation was 100%. Twenty-three patients (33%) had T1a disease. The median (interquartile range [IQR]) tumor size was 4.6cm [3.7-5.5]; it was 3.3cm [3.0-3.6] in those receiving single fraction (n = 23), and 5.3cm [4.6-6.0] in those receiving 3-fraction SBRT (n = 47). During real-time pre-treatment quality assurance review, 10 cases (14.3%) required resubmission for protocol deviation, 2119 variables were assessed at final review, and final protocol compliance was 99.3%. Seven (10%) patients experienced grade 3 treatment-related adverse events, with no grade 4 or 5 events observed. Eleven (16%) patients reported no adverse events. Local control was 100% throughout the lifetime of the trial (p<0.001). Cancer-specific survival was also 100% throughout the lifetime of the trial. Freedom from distant failure (95% CIs) at 1 and 3 years was 99% (90-100%). Overall survival (95% CIs) at 1 and 3 years was 99% (90-100%) and 82% (70-89%), respectively. Baseline mean eGFR (95% CI) was 61.1 mLs/min (56.6; 65.6) and reduced by -10.8 mLs/min (-13.0; -8.6) by 1-year, by -14.6 mLs/min (-17.0; -12.2) by 2-years and plateaued thereafter.

CONCLUSION

In the first multicenter prospective trial of a non-surgical primary RCC cohort, enrolling mostly T1b+ disease, SBRT was an effective treatment strategy with no observed local failures. We observed an acceptable side effect profile and renal function after SBRT. These outcomes support the design of a future randomized clinical trial of SBRT versus surgery for primary RCC. The trial was registered with ID: NCT02613819.

Multi-Institutional Analysis of Metastasis Directed Therapy with or without Androgen Deprivation Therapy in Oligometastatic Castration Sensitive Prostate Cancer

PURPOSE/OBJECTIVE(S)

Several prospective trials in oligometastatic castration sensitive prostate cancer (omCSPC) have shown metastasis-directed therapy (MDT) can delay time to progression and initiation of androgen deprivation therapy (ADT) compared to observation. However, the optimal integration of ADT with MDT remains unclear. Here we report a multi-national, multi-institutional retrospective cohort of omCSPC treated with MDT to characterize the long-term outcomes of patients treated with MDT alone or in combination with ADT.

MATERIALS/METHODS

Patients with a controlled primary site and omCSPC (defined as ≤ 5 lesions on conventional imaging) treated with MDT with or without concurrent ADT and with at least 36 months follow-up were retrospectively screened across 13 institutions. The primary endpoints included biochemical progression free survival (bPFS) and radiographic progression free survival (rPFS) calculated using Kaplan-Meier method and stratified by treatment group (MDT alone vs MDT + ADT). Multivariable Cox regression was performed adjusted for variables found to be prognostic on univariate analysis.

RESULTS

Among 414 patients screened, a total of 263 patients treated between 2003 and 2018 met inclusion criteria and included. Of these, 105 received MDT alone and 158 received MDT+ADT, with median follow-up of 49.5 and 54.5 months, respectively. The majority were metachronous (90%) and had bone lesions (60%). Median ADT duration was 21.3 months (IQR 12.0- 31.9). Patients who received ADT vs. no ADT had poorer prognostic features including 23% vs. 1% synchronous (p<0.001), and 55% vs 40% Gleason 8-10 (p = 0.012). ADT use was associated with a better 5-year bPFS 24% vs 11% (p<0.0001) and rPFS 41% vs 29% (p<0.001). On multivariable Cox regression adjusting for post-MDT PSA nadir and salvage therapy, ADT use maintained significance for both bPFS (HR 0.51 (0.36, 0.71), p<0.001) and rPFS (HR 0.67, 95% CI 0.46-0.96, p = 0.03).

CONCLUSION

Long-term outcomes with MDT alone suggest a small proportion of patients experience sustained disease control. The addition of ADT appears to improve rPFS, however prospective studies are needed in order to allow for personalization of care in patients with omCSPC.

Patterns of Failure Following Dose-escalated Chemoradiotherapy for Fluorodeoxyglucose Positron Emission Tomography Staged Squamous Cell Carcinoma of the Oesophagus

AIMS

To analyse outcomes and patterns of failure following dose-escalated definitive chemoradiotherapy (CRT) for oesophageal squamous cell carcinoma using fluorodeoxyglucose positron emission tomography for staging and treatment planning.

MATERIALS AND METHODS

A retrospective review of patients with oesophageal squamous cell carcinoma receiving definitive CRT to a dose of ≥56 Gy was conducted. Patient and tumour characteristics, treatment received and first sites of relapse were analysed.

RESULTS

Between 2003 and 2014, 72 patients were treated with CRT to a median dose of 60 Gy (range 56-66 Gy). The median age was 63 years; most (61%) were stage III/IVa. The median follow-up was 57 months. Three year in-field control, relapse-free survival and overall survival was 64% (95% confidence interval 50-75%), 38% (95% confidence interval 27-50%) and 42% (95% confidence interval 30-53%), respectively. Of the 41 failures prior to death or at last follow-up date, isolated locoregional relapse occurred in 16 patients (22%) with isolated in-field recurrence in 11 patients (15%). Distant failure as first site of relapse was present in 25 patients (35%). No in-field failures occurred in the 11 patients with cT1-2, N0-1 tumours. The median survival for cT4 tumours was 8 months, with five of eight patients developing local progression within the first 6 months.

CONCLUSIONS

Dose-escalated radiotherapy was associated with promising rates of in-field local control, with the exception of cT4 tumours. Distant failure remains a significant competing risk. Our data supports the need for current trials re-examining the role of dose escalation in the modern era.