"Moderately Hypofractionated" Radiotherapy with a Simultaneously Integrated Boost for Synchronous Treatment of Prostate and Anorectal Cancer

PURPOSE/OBJECTIVE(S)

Data suggest safety and efficacy of 1.8-2.0 Gy per day radiotherapy (RT) with sequential boost regimens for patients with synchronous prostate and anorectal cancers. Emergence of 25-28 fraction (fx) prostate cancer RT regimens has enabled simultaneously integrated boost techniques to treat the prostate and anorectum (HypoRT), but limited reports exist to support the safety or efficacy of this approach. We aimed to assess oncologic outcomes and patient-reported outcomes (PRO)- and physician-reported adverse effects (AEs) of HypoRT for patients with synchronous prostate and anorectal cancers.

MATERIALS/METHODS

This was a retrospective cohort study of patients synchronously diagnosed with prostate and rectal cancer or anal canal squamous cell carcinoma (ASCC) treated with a HypoRT technique and concurrent chemotherapy between 2014-2022. Outcomes included prostate cancer biochemical recurrence (BCR), anorectal cancer recurrence, progression-free (PFS) and overall survival (OS). Acute and late gastrointestinal (GI) and genitourinary (GU) AEs and PRO were prospectively collected using common terminology criteria for AEs (CTCAE) and PRO-CTCAE.

RESULTS

Twelve patients were included. Patients had ECOG 0-1; median age was 71 years (51-82). Rectal cancer (n = 11) characteristics included T3 (91%), N1-2 (73%), M0 (73%); 3 had M1a disease suitable for curative-intent treatment. One patient had T2N1M0 ASCC. Prostate cancer risk groups included low (9%), intermediate (45%), and high/very high risk (46%). HypoRT included 45-50 and 67.5 Gy in 25 fx (33%), 46.8-52 and 70.2 Gy in 26 fx (17%), and 44.8-56 and 70 Gy in 28 fx (50%), to the pelvis-anorectum and prostate. Patients with rectal cancer received concurrent capecitabine. Nine (82%) patients with rectal cancer had surgical resection; 1 was R1. The patient with ASCC received concurrent 5-fluorouracil and mitomycin C. Six patients (50%) received androgen suppression. All patients completed treatment successfully but 1 patient with rectal cancer did require hospitalization with treatment break due to GI AEs. Median follow was 60 months (13-103). Oncologic outcomes and AEs are in the table. No patient experienced prostate cancer BCR or ASCC progression. Four of 11 patients with rectal cancer progressed including 3 distant metastases, each amongst initial M1a patients, and 1 local-regrowth in a patient managed non-operatively.

CONCLUSION

HypoRT can effectively be utilized for patients with synchronous prostate and anorectal cancer. Physician assessed AEs compared favorably with prior data, however, further work is needed to understand differences in physician and patient experience. HypoRT may serve as another suitable option in the management of this complex clinical scenario.

Non-Operative Management of Rectal or Anal Canal Adenocarcinoma: National Cancer Database Analysis of the Impact of Disease, Treatment, and Social Determinants of Health on Overall Survival

PURPOSE/OBJECTIVE(S)

For select patients with rectal or anal canal adenocarcinoma (RA-ACA), a non-operative management (NOM) strategy utilizing definitive radiotherapy (RT) has emerged as an option with the goal to improve quality of life compared with surgical management while maintaining similar oncologic outcomes. Disease and treatment characteristics as well as social determinants of health have been associated with access to care and health outcomes, and we hypothesized that such factors would impact overall survival (OS) amongst patients who received a NOM approach. The purpose of this study was to explore the influence of patient demographics, disease characteristics, and social determinants of health on OS amongst those receiving NOM utilizing the National Cancer Database (NCDB).

MATERIALS/METHODS

We identified patients at least 18 of years of age diagnosed with clinical stage 1-3 RA-ACA from 2004-2018. The NOM cohort included patients who received RT and either refused surgery or surgery was not recommended in their treatment. Patients were excluded if receipt of chemotherapy or RT were unknown, received RT to a site outside of the pelvis, or received palliative-intent treatment. OS was estimated using the Kaplan-Meier method. Univariable and multivariable (MVA) Cox proportional hazards model was used to assess characteristics associated with OS. Analyses were performed using STATA (version 17, College Station, TX). A p<0.05 was considered statistically significant.

RESULTS

A total of 12,409 patients were identified as the NOM cohort. The median OS was 48.8 months (95% CI: 46.8-50.6). On MVA, variables associated with poorer OS included age ≥ 70 vs 50-69, male sex, Charlson-Deyo Score ≥ 1 vs 0, insurance status (no insurance, Medicaid or Medicare vs. private), geographical region (South, Midwest or West vs. Northeast), rural urban density vs metro/urban, treatment in a community facility vs academic, year of diagnosis (2004-2011 vs. 2012-2018), clinical T4 vs T1, clinical N1 or N2 vs N0, and grade 3 vs 1 (all p<0.05). Treatment with a RT dose < 45 Gy vs. 45-54 Gy (HR: 2.24, 95% CI: 2.07-2.44), but not > 55 Gy vs. 45-54 Gy, and omission of chemotherapy (HR: 1.28, 95% CI: 1.16-1.43) were associated with poorer OS.

CONCLUSION

Patient, disease, treatment, and social determinants of health may influence OS amongst patients with RA-ACA who receive a NOM approach. Further work is needed to determine if the influence on OS can be explained, in part, by patients' lack of access to the intense surveillance necessary and/or the potential need for subsequent surgical management. Heightened awareness of these differential outcomes is needed to assist in patient selection and to successfully address barriers in access to optimize outcomes for patients who receive NOM.

Electrocardiogram with Artificial Intelligence Assessment as a Predictor of Cardiac Events and Overall Survival in Patients Receiving Radiotherapy for Esophageal Cancer

PURPOSE/OBJECTIVE(S)

Neoadjuvant (chemo)radiotherapy (RT) has demonstrated an overall survival (OS) benefit in esophageal cancer and constitutes part of the standard of care trimodality therapy. Unfortunately, subsequent cardiac toxicity can reduce the benefit of treatment. Our group aimed to study whether data from electrocardiograms (ECGs) could predict clinical outcomes and cardiac events after RT for esophageal cancer, allowing for identification of and early intervention for patients at high risk for cardiac toxicity.

MATERIALS/METHODS

Included patients received at least 41.4 Gy of pre-operative or definitive photon or proton RT for esophageal cancer from 2015 through July 2022. All ECGs were assessed using a previously validated artificial intelligence assessment for atrial fibrillation (AF) and reduced ejection fraction (rEF) (Noseworthy et al. Lancet 2022). The model determined propensities for the development of multiple cardiac events, including AF and heart failure (HF). Medical records were reviewed for cardiac events and conditions prior to and after RT.

RESULTS

A cohort of 491 patients was assembled, with 301, 121, and 364 patients having an ECG prior to, during, and after RT, respectively. Of these, 84% had malignancy in the lower third of the esophagus and 48% underwent esophagectomy. At last follow-up relative to baseline assessment, patients had increased propensity for rEF (median 0.013, interquartile range (IQR): 0.001-0.038 vs. median 0.022, IQR: 0.011-0.074, p < 0.0001) and AF (median 0.16, IQR: 0.04-0.40 vs. median 0.048, IQR: 0.01-0.19, p < 0.0001). Increases in AF propensity were associated with reduced OS (hazard ratio (HR) = 1.10 per 0.1 increase, 95% confidence interval (CI): 1.03-1.17, p = 0.0071). Baseline rEF propensity was predictive of future HF events (HR = 1.14, 95% CI: 1.07-1.22, p < 0.001) for all patients or after excluding the 172 (35%) patients with baseline HF (HR = 1.45, 95% CI: 1.19-1.76, p < 0.001). Among patients who did not have HF prior to radiotherapy, the development of HF was associated with reduced OS (HR = 1.60, 95% CI: 1.10-2.32, p = 0.014). Currently available cardiac dosimetric parameters, including heart mean/max doses, did not significantly correlate with cardiac outcomes. Patients who underwent esophagectomy had improved OS (HR = 0.62, 95% CI: 0.47-0.82, p = 0.0008) and were not more likely to develop cardiac toxicity.

CONCLUSION

This analysis suggests that chemoradiotherapy for esophageal cancer can have significant impacts on a patient's propensity for cardiac events, which are associated with reduced OS. ECGs carry the potential to identify patients at greater risk for such events, and baseline ECGs with artificial intelligence assessment could select patients for increased surveillance or early intervention to further optimize the therapeutic ratio of RT.

Patient-Reported Adverse Effects in 15-Fraction Pancreatic Cancer Radiation Therapy

PURPOSE/OBJECTIVE(S)

Fifteen-fraction radiotherapy (RT) regimens have emerged as a standard option in the treatment of patients with pancreas cancer. Patient-reported outcomes (PROs) during and after pancreas cancer RT have not been well characterized. There is an even greater paucity of data among patients treated with 15-fraction regimens. We aimed to characterize gastrointestinal (GI) PROs in a cohort of patients treated with 15-fraction pancreas RT.

MATERIALS/METHODS

This was an IRB-approved retrospective cohort study including patients with primary pancreas tumors treated with pre-operative or definitive 15-fraction RT from 2013 to 2022. PROs, including anorexia, nausea, diarrhea, stool incontinence, and abdominal pain, were prospectively collected and characterized per PRO-common terminology criteria for adverse events (PRO-CTCAE). Acute PROs were defined as occurring during RT through 110 days post-RT but prior to oncological surgery. Grade 3 or 4 PROs were respectively scored as "quite a bit" or "very much" in symptom interference questions, "frequently" or "almost constantly" in symptom frequency questions, and "severe" or "very severe" in symptom severity questions.

RESULTS

A total of 330 patients were analyzed. Patient characteristics included a median age of 67 years (IQR: 60 - 72), ECOG 0-1 (96%), and male sex (56%). Most patients had pancreatic ductal adenocarcinoma (96%). Resectability status included resectable (12%), borderline resectable (46%), and locally advanced (42%). 37% had lymph node involvement. 97% of patients received neoadjuvant chemotherapy and 98% received concurrent chemotherapy, most commonly with 5-fluorouracil or capecitabine (88%) or gemcitabine (11%). 99% were treated with intensity modulated RT. Median RT dose was 4500 cGy (IQR 4500 - 4500) to gross disease with margin and 3750 cGy (IQR 3750 - 3750) to elective nodal regions. 59% proceeded with oncologic resection. Grade 3 or higher acute PROs are demonstrated in the table.

CONCLUSION

Often considered more sensitive than physician assessments, PROs provide vital metrics that allow for a better understanding of the patient experience during cancer treatment. We report a comprehensive assessment of prospectively collected PROs per standardized PRO-CTCAE with the goals of raising awareness of the patient experience during 15-fraction pancreas cancer RT and helping guide future clinical trial designs focused on patient quality of life endpoints.

Determining the Minimal Clinically Important Difference of the FACT-E to Evaluate the Change in the Quality of Life of Patients with Esophageal Cancer Treated with Curative Radiotherapy

PURPOSE/OBJECTIVE(S)

Patients with esophageal cancer (EC) are often treated with radiotherapy (RT). The Functional Assessment of Cancer Therapy-Esophageal (FACT-E) is a health-related quality of life (QOL) instrument validated in patients with EC. The aim of this study was to determine the minimal clinically important difference (MCID) for FACT-E subscales, to allow for meaningful evaluation of the effect of RT on EC patient's QOL.

MATERIALS/METHODS

We evaluated patients with EC, treated with curative intent RT, who completed the FACT-E at baseline and end of treatment (EOT). We calculated the MCID for the FACT-E subscales using anchor-based and distribution-based approaches. In the anchor-based approach we determined improvement and deterioration based on the overall health assessment from the PROMIS-10 as the anchor. We modeled the change in domain scores with age-adjusted regressions to determine the difference in classifications. For distribution-based analysis, we considered 0.3 and 0.5 standard deviation (SD). We averaged MCID for improvement and deterioration separately across timepoints, by approach, and we report MCID ranges as the minimum and maximum values across methods.

RESULTS

Our cohort included 210 patients with EC, 96.7% white, 85.7% males, and 32.9% treated with photon with a median dose of 50 Gy (IQR 50-50) and a median fraction number of 25(IQR 25,25). The median age at RT was 67.6 years (IQR 60.9,73.7). The social domain had the lowest MCID (deterioration and improvement 0.9-1.9), while the widest MCID range, proportionally to the measure, was associated with the Fact-E total score (2.1-5.6 for improvement, and 3.7-5.6 for deterioration). MCID estimates from 0.3 SD were in exact agreement with the anchor-based deterioration estimates for the physical domain (2.3), and improvement estimates for the Trial Outcome Index (6.1).

CONCLUSION

We determined the MCID for the FACT-E domains, using a combination of anchor- and distribution-based approaches. These findings are critical to determine whether there is meaningful change in the QOL of individuals with EC treated with curative RT.

Single Institutional Experience Using Radiation Therapy in the Treatment of Neuroendocrine Tumor Primary and Metastatic Lesions

PURPOSE/OBJECTIVE(S)

The role of radiation therapy (RT) in the treatment of patients with neuroendocrine tumors (NETs) has not been well established. We aim to report on our experience using RT as part of curative or palliative treatment in patients with NET.

MATERIALS/METHODS

This was an IRB approved single-institutional retrospective cohort study including patients with NET who received curative- or palliative-intent RT from 2013-2022. Outcomes included cumulative incidence of local progression (LP) and overall survival (OS). Univariate and multivariate methods were used to assess disease and treatment characteristics associated with outcomes. RT dose was converted to biologically effective dose (BED10), assuming α/β = 10 Gy.

RESULTS

Sixty-six patients who received treatment to 89 total lesions were included for analysis. The median age at RT was 56 years (range: 20-95). ECOG performance status was 0-1 in 49 and 56% were male. Primary tumor origin included: 28 pancreas, 12 lung, 8 small intestine, 5 colorectal, 2 stomach, and 11 unknown/other primary cancers. Tumor grade included 1 (62%), 2 (1%), 3 (17%) or unknown (18%). 20% were functional. 43% of patients had metastatic disease at diagnosis, 24 were initially M0 and developed M1 disease in their disease course, and 12 remained M0. RT was delivered to the primary tumor (59%) or metastatic sites (41%). Treatment was either curative-intent (37%), including "curative" intent oligometastasis direct therapy, or palliative-intent (63%). For the 27 patients with M1 disease at time of RT, 1 had all sites controlled by local therapies at the time of RT. The location of the treated lesions included 17 pancreas, 13 bone, 12 thorax, 4 colorectal, 3 small bowel, and 15 other. Median RT dose and number of fractions were 30 Gy (IQR: 20-45) and 5 (IQR: 5-15). The median BED10 was 48 (IQR: 28-65) for all lesions and 60 (IQR: 58-69) for lesions treated curatively. 21 (32%) patients received concurrent systemic therapy with RT. The median follow-up per patient and per lesion were 15 months (IQR: 6-33) and 13 months (IQR: 5-28). The median OS was 34.5 months (95% confidence interval [CI]: 16.6-NE). The 3-year cumulative incidence of local progression was 15% (95% CI: 8-28%). BED10 was not associated with LP.

CONCLUSION

These data support the use of RT as a highly effective local treatment modality in the care of patients with either localized or metastatic NET.

Detectable Post-operative Circulating Tumor Human Papillomavirus (HPV) DNA And Association with Recurrence in Patients with HPV-Associated Oropharyngeal Squamous Cell Carcinoma

PURPOSE

  To determine the rate of detectability of ctHPVDNA after surgery but before adjuvant therapy in patients with HPV-associated oropharyngeal squamous cell carcinoma (HPV(+)OPSCC) and to investigate whether detectable ctHPVDNA at this time point may be associated with risk of recurrence.

METHODS AND MATERIALS

 Prospectively collected samples from patients with OPSCC were examined in a blinded fashion using a multi-analyte PCR assay. 45 samples were collected from HPV(+)OPSCC patients pre-op (prior to any treatment), and 159 samples post-op (before or at the start of adjuvant RT). Samples were identified via the radiation oncology biobank or via participation in a clinical trial. RT consisted of 60 Gy +/- cisplatin or de-escalation (30 Gy to 36 Gy in 20 b.i.d. fractions + docetaxel). 32 patients had paired samples available pre and post-op for the primary analysis. Additional exploratory analyses including associations of patient and tumor characteristics with recurrence were assessed using Cox proportional hazards models for all 159 post-op samples.. Detectability of ctHPVDNA was compared across groups utilizing logistic regression. Estimates of recurrence free survival (RFS) were made using Kaplan-Meier (KM).

RESULTS

In a paired analysis of 32 pre and post-op timepoints, 94% of patients had detectable ctHPVDNA pre-op and 41% post-op. RFS at 18 months was 83% (95% CI: 47-95%) for patients with detectable post-op ctHPVDNA compared to 100% for patients with undetectable post-op ctHPVDNA (p=.094).In an exploratory analysis of non-paired post-op samples, ctHPVDNA was detectable in 26% (41 of 159) of patients (median of 22 days post-op). Age (1.06, p=0.025), LVSI (OR 3.17, p=0.011) and ENE (OR=5.67, p=0.001) were associated with detectable ctHPVDNA after surgery. Detectable post-op ctHPVDNA was significantly associated with RFS (p<0.001).

CONCLUSION

Amongst patients with detectable pre-op ctHPVDNA, a significant proportion have detectable post-op ctHPVDNA in paired post-op samples, collected prior to the initiation of adjuvant radiation therapy. Future prospective study is warranted to investigate the association of detectable post-op ctHPVDNA with recurrence, including in comparison to established clinical and pathologic risk factors.