Survival outcomes for women with a solitary extracranial metastasis from breast cancer.

BACKGROUND: Aggressive metastasis directed treatment of extracranial oligometastatic breast cancer with the aim of increasing disease-free survival has emerged as a new potential treatment paradigm, however there is currently a lack of data to assist in identifying the subset of patients who will potentially benefit most. This single-institute retrospective cohort study aimed to evaluate survival outcomes for patients with a solitary extracranial metastasis from breast cancer and to assess for significant prognostic factors. METHODS AND MATERIALS: Medical records of 70 female breast cancer patients with a solitary extracranial metastasis actively managed at the Peter MacCallum Cancer Centre (PMCC) Melbourne Campus between 2000 and 2019 were reviewed. Kaplan-Meier curves were used to estimate overall survival (OS), local progression free survival (LPFS) and distant progression free survival (DPFS). RESULTS: Median follow-up period was 9.4 years. The study included 40 hormone receptor positive/HER2 negative (HR+HER2-), 14 hormone receptor positive/HER2 positive (HR+HER2+), 3 hormone receptor negative/HER2 positive (HR-HER2+), 9 triple negative (TNBC) and 4 unclassified breast cancer patients. 5-year OS rate for all patients was 46%, LPFS rate was 56% and DPFS was 20%. Tumour receptor group had a statistically significant association with OS and DPFS rates. TNBC patients had significantly poorer OS and DPFS rates in comparison to HR+HER2-patients. CONCLUSION: Among patients with a solitary extracranial metastasis from breast cancer, TNBC was associated with the poorest OS and DPFS rates. Identification of other significant prognostic factors for oligometastatic breast cancer patients may inform guidelines for metastasis directed treatments.

Impact of advancing age on treatment and outcomes in anal cancer.

BACKGROUND: Chemoradiotherapy (CRT) for squamous cell carcinoma of the anus (SCCA) may cause significant toxicity, and concerns exist about its tolerability in the elderly. The authors compared tolerability and outcomes across the age groups following CRT for SCCA. METHODS: Single-institution retrospective analysis of patients with localized SCCA treated with CRT. CRT was standardized at 50.4-54 Gy, with concurrent infusional 5-fluorouracil and mitomycin C. Patients were arbitrarily categorized into three groups: Group 1 - age < 50 years; Group 2 - age ≥ 50 and < 70 years; and Group 3 - age ≥ 70 years. RESULTS: Of 284 patients identified, 278 were evaluable. The number of patients in each age group was: Group 1 - 51; Group 2 - 140; and Group 3 - 93. Baseline and treatment characteristics, tumor stage, rates of overall acute toxicity, need for unplanned treatment breaks and chemotherapy delivery were largely similar across the age groups. However, nine patients in Group 3 did not complete CRT, compared with five and none in Groups 1 and 2, respectively (p = 0.006). In addition, five patients in Group 3 had diarrhea requiring treatment break, compared with none in the other two groups (p = 0.004). At a median follow-up 5.3 years, there was no significant difference in overall survival (p = 0.11), disease-free survival (p = 0.22) or local-recurrence free survival (p = 0.34), across the three age groups. CONCLUSIONS: CRT is safe and tolerable in the elderly age group, and provides equivalent disease control rates compared with the younger age group. Age alone should therefore not preclude aggressive curative treatment.

Plan of the day selection for online image-guided adaptive post-prostatectomy radiotherapy.

PURPOSE: To compare the cone-beam CT (CBCT) soft tissue localization disparity between radiation oncologists (RO) and radiation therapy technologists (RTT) in a novel online protocol of image-guided adaptive radiotherapy to the postoperative prostate bed. METHOD: Using the planning CT and pre-treatment CBCTs from the first week of radiotherapy, four adaptive plans of different sizes were derived for each of eight post-prostatectomy patients. Four ROs collectively defined the reference answer, i.e. the plan of the day and isocentre correction for 40 CBCTs taken in weeks 2-6 of treatment for each patient. RTTs were randomly assigned five of these CBCTs; and asked to record their plan of the day selection and isocentre correction. RTT selection and reference answers were compared. The distance between the RTT selection and the reference answer was calculated. RESULTS: A total of 33 RTTs took part in this study. The average difference in CTV volume (reference answer-RTT selection) was 1.32 cm(3) (SD 29 cm(3)) overall. The average difference between reference answer and RTT isocentre coordinates was SI 1mm (SD 4.8mm), LR 1.1mm (SD 4.0mm) and AP -0.2mm (SD 3.9 mm). Distance of superior 8mm, inferior 6mm, left 4mm, right 2mm, anterior 6mm and posterior 6mm covered 100% of the CTV in 90% of fractions. CONCLUSION: The difference between RTT and RO selection of adaptive volumes is small and can be accounted for in a clinically acceptable CTV to PTV margin. Adaptive post-prostatectomy radiotherapy is feasible, in the setting of an academic center although at the moment, we have insufficient evidence to suggest that margins can yet be reduced with IGART with the current protocol.

Evaluation of variability in seroma delineation between clinical specialist radiation therapist and radiation oncologist for adjuvant breast irradiation.

PURPOSE: Breast cancer is managed by a multidisciplinary team with a goal for the timely provision of high quality care. Given radiation oncologist (RO) time constraints, an opportunity arises for task delegation of breast seroma target delineation to an advanced practice clinical specialist radiation therapist (CSRT) with clinical and technical expertise to facilitate treatment planning. To explore this further, we quantitatively evaluated the variability in post-surgical seroma delineation between the CSRT and ROs. METHODS: Specialized site specific training was provided to the CSRT, who, with 7 ROs, independently contoured the seroma and graded its clarity, using the cavity visualization score (CVS), for 20 patients with clinical stage Tis-2N0 breast tumors. The conformity indices were analyzed for all possible pairs of delineations. The estimated "true" seroma contour was derived from the RO contours using the simultaneous truth and performance level estimation algorithm. Generalized kappa coefficient and center of mass metrics were used to examine the performance level of the CSRT in seroma delineations. RESULTS: The CVS of the CSRT correlated well with the mean RO-group CVS, (Spearman ρ = 0.87, P < .05). The mean seroma conformity index for the RO group was 0.61 and 0.65 for the CSRT; a strong correlation was observed between the RO and CSRT conformity indices (Spearman ρ = 0.95, P < .05). Almost perfect agreement levels were observed between the CSRT contours and the STAPLE RO consensus contours, with an overall kappa statistic of 0.81 (P < .0001). The average center of mass shift between the CSRT and RO consensus contour was 1.69 ± 1.13 mm. CONCLUSIONS: Following specialized education and training, the CSRT delineated seroma targets clinically comparable with those of the radiation oncologists in women with early breast tumors suitable for accelerated partial breast or whole breast radiotherapy following lumpectomy. This study provides support for potential task delegation of breast seroma delineation to the CSRT in our current multidisciplinary environment. Further study is needed to assess the impact of this role expansion on radiotherapy system efficiency.