Jethwa, Krishan R.

No standard treatment paradigm exists for previously irradiated locally recurrent rectal cancer (PILRRC). Carbon-ion radiotherapy (CIRT) may improve oncologic outcomes and reduce toxicity compared with combined modality therapy (CMT). Eighty-five patients treated at Institution A with CIRT alone (70.4 Gy/16 fx) and eighty-six at Institution B with CMT (30 Gy/15 fx chemoradiation, resection, intraoperative electron radiotherapy (IOERT)) between 2006 and 2019 were retrospectively compared. Overall survival (OS), pelvic re-recurrence (PR), distant metastasis (DM), or any disease progression (DP) were analyzed with the Kaplan–Meier model, with outcomes compared using the Cox proportional hazards model. Acute and late toxicities were compared, as was the 2-year cost. The median time to follow-up or death was 6.5 years. Median OS in the CIRT and CMT cohorts were 4.5 and 2.6 years, respectively (p ≤ 0.01). No difference was seen in the cumulative incidence of PR (p = 0.17), DM (p = 0.39), or DP (p = 0.19). Lower acute grade ≥ 2 skin and GI/GU toxicity and lower late grade ≥ 2 GU toxicities were associated with CIRT. Higher 2-year cumulative costs were associated with CMT. Oncologic outcomes were similar for patients treated with CIRT or CMT, although patient morbidity and cost were lower with CIRT, and CIRT was associated with longer OS. Prospective comparative studies are needed.

AbstractBackgroundAdrenal metastasis is the most common adrenal malignancy and can be bilateral in up to 43% of patients. Radiotherapy (RT) is one option available to treat adrenal metastases. The risk of primary adrenal insufficiency (PAI) after adrenal RT is unclear.ObjectiveDetermine the incidence and the timeline of PAI in patients undergoing adrenal RT.Design, Setting and ParticipantsSingle‐centre longitudinal retrospective cohort study of adult patients with adrenal metastases treated with RT between 2010 and 2021.ResultsOf 56 patients with adrenal metastases treated with adrenal RT, eight (14.3%) patients developed PAI at a median of 6.1 months (interquartile range [IQR]: 3.9–13.8) after RT All patients developing PAI had either unilateral RT in the setting of contralateral adrenalectomy or bilateral adrenal RT. Patients who developed PAI received a median RT dose of 50 Gy (IQR: 44–50 Gy), administered in a median of five fractions (IQR: 5–6). Treated metastases decreased in size and/or metabolic activity on positron emission tomography in seven patients (87.5%). Patients were initiated on hydrocortisone (median daily dose of 20 mg, IQR: 18–40) and fludrocortisone (median daily dose of 0.05 mg, IQR: 0.05–0.05 mg). At the end of the study period, five patients died, all due to extra‐adrenal malignancy, at a median time of 19.7 months (IQR: 16–21.1 months) since RT and median time of 7.7 months (IQR: 2.9–12.5 months) since the diagnosis of PAI.ConclusionPatients receiving unilateral adrenal RT with two intact adrenal glands have a low risk of PAI. Patients receiving bilateral adrenal RT have a high risk of PAI and require close monitoring.

255 Background: During the COVID-19 pandemic, Twitter has been instrumental in accelerating knowledge dissemination and forging collaborations within the medical community and amongst patient advocates. Tweetchats within Twitter are scheduled conversations on a specific topic. In oncology, Tweetchats have been used by cancer advocates to spread awareness and for patient and caregiver education. A colorectal cancer (CRC) specific tweetchat did not previously exist. This abstract describes the creation, and experiences with a CRC specific tweetchat. Methods: The #CRCTrialsChat tweetchat was created by a patient advocate for colorectal cancer patients, caregivers and clinicians to meet and exchange clinical trial-related information. Two gastrointestinal (GI) medical oncologists and two radiation oncologists were enlisted as moderators. The topic for each session is chosen by the patient advocate, who creates an outline and divides the content, which is designed to last a one hour session. The idea is to create engaging, technical, but easy to understand content. Each moderator then works on the answers to their assigned section, which is edited to fit tweet character limit. Sessions may also have guest moderators with expertise on a specific topic. Through tweeting, moderators answer specific questions that come up during the session and later. Results: To date, we have had four sessions covering the following topics: Clinical trial basics, CRC Updates from ASCO22, ClinicalTrialFinders and BRAF-mutated tumors. The content created has been simple and engaging, the format has functioned smoothly, and the reach of #CRCTrialsChat has been steadily increasing. After the most recent session on BRAF in September 2022, the @CRCTrialsChat has 281 followers, 17K impressions and 14.6K profile visits, a reflection of its excellent content. From a clinician perspective, this is a great format to interact with colleagues, discuss enrolling trials and also become familiar with using Twitter. Conclusions: A CRC clinical trial focused tweetchat is an engaging way to deliver trial-related content to an audience of clinicians, patients and caregivers. The current format appears to be an effective way to create and disseminate information. Future sessions will focus on ctDNA, molecular markers such as KRAS and HER2, and rectal cancer trials. Our hope is that #CRCTrialsChat will stimulate continued patient and clinician engagement, increase awareness of clinical trials, enhance trial participation and initiate patient-centric research and collaborations.

Although uncommon, extrahepatic cholangiocarcinoma (EHCC) is a deadly malignancy, and the treatment approaches remain controversial. While surgery remains the only cure, few patients are candidates for resection up front, and there are high rates of both local and distant failure following resection. Herein, we systematically review the available evidence regarding treatment approaches for patients with EHCC, including surgery, radiation, and chemotherapy. The evidence regarding treatment outcomes was assessed using the Population, Intervention, Comparator, Outcome, and Study design (PICOS) framework. A summary of recommendations based on the available literature is outlined for specific clinical scenarios encountered by providers in the clinic to guide the management of these patients.

Background and Purpose: Chemotherapy followed by margin-negative resection (R0) is the treatment of choice for patients with localized pancreatic ductal adenocarcinoma (PDAC). Neoadjuvant multiagent chemotherapy (MAC) or MAC then radiotherapy (RT) may optimize surgical candidacy. The purpose of this study was to compare pathologic outcomes of MAC followed by conventionally fractionated radiotherapy (CRT) versus stereotactic body radiotherapy (SBRT) for patients with resected PDAC. Methods: Patients diagnosed with nonmetastatic PDAC between 2012 and 2017 and who received preoperative MAC or MAC+RT were identified in the National Cancer Database. Variables associated with R0 and overall survival were identified with logistic regression and Cox analysis (P<0.05). Results: A total of 5273 patients were identified (MAC: 3900, MAC+CRT: 955, MAC+SBRT: 418). The median RT dose/fraction (fx) in the MAC+CRT and MAC+SBRT cohorts was 50.4 Gy/28 fx and 33 Gy/5 fx. Patients receiving MAC+CRT versus MAC+SBRT had similar rates of ypT3-T4 disease (54% vs. 58%, P=0.187), R0 (87% vs. 84%, P=0.168), and pathologic complete response (pathologic complete response; 6% vs. 4%, P=0.052), however, MAC+CRT was associated with less regional lymphatic disease (ypN+: 28% vs. 41%, P<0.001). The median overall survival of patients receiving MAC+CRT versus MAC+SBRT was 24.6 versus 29.5 months (P=0.045). Conclusions: For patients with resected PDAC, MAC+CRT, and MAC+SBRT had similar rates of R0 and pathologic complete response, although MAC+CRT was associated with lower ypN+. Prospective evaluation of neoadjuvant RT regimens with attention to radiation therapy design is warranted.

Anal canal and peri-anal squamous cell carcinomas (ASCCs) are relatively rare cancers that affect approximately 8000 patients per year in the United States [...]

AbstractBackgroundIncreased risk of a second primary malignancy (SPM) before or after diagnosis of anal squamous cell carcinoma (ASCC) has been reported in a previous single‐institution study. We hypothesize that patients diagnosed with ASCC are at increased risk for developing SPMs before or after the diagnosis of ASCC. The primary objective of this study was to identify the diagnoses of cancer most likely to occur as SPMs before or after ASCC.MethodsThis work employs the Surveillance, Epidemiology, and End Results (SEER) Program registry data to conduct a US‐population‐based study of patients diagnosed with ASCC between 1975 and 2016. In patients diagnosed with ASCC, we evaluated the risk of SPMs and the risk of developing ASCC as an SPM after another cancer using standardized incidence ratios (SIR) for all SPMs by calculating the ratio of observed events in the ASCC cohort compared to expected (O/E) events in a matched reference cohort of the general population.ResultsA total of 7,594 patients with primary ASCC were included. Patients with ASCC were at increased risk of the diagnosis of an SPM (SIR = 1.45), particularly cancers of the lung, vulva, oropharynx, or colon. Patients with ASCC had an increased rate of previous malignancy (SIR = 1.23), especially Kaposi sarcoma or vulvar cancer. Overall elevated incidence of SPMs was unrelated to prior radiation treatment. Radiation treatment was associated with increased risk for SPMs in the female genital system but appeared protective against prostate cancer as SPMs.ConclusionsOur findings support increased surveillance and screening for second malignancies in patients with these diagnoses, as patients with ASCC are often either survivors of a prior cancer diagnosis or are at increased risk of developing later malignancies.

Abstract Background Patterns of recurrence and survival with different surgical and radiotherapy (RT) techniques were evaluated to guide RT target volumes for patients with temporal lobe glioma. Methods and Materials This retrospective cohort study included patients with World Health Organization grades II to IV temporal lobe glioma treated with either partial (PTL) or complete temporal lobectomy (CTL) followed by RT covering both the parenchymal and dural resection bed (whole-cavity radiotherapy [WCRT]) or the parenchymal resection bed only (partial-cavity radiotherapy [PCRT]). Patterns of recurrence, progression-free survival (PFS) and overall survival (OS) were evaluated. Results Fifty-one patients were included and 84.3% of patients had high-grade glioma (HGG). CTL and PTL were performed for 11 (21.6%) and 40 (78.4%) patients, respectively. Median RT dose was 60 Gy (range, 40-76 Gy). There were 82.4% and 17.6% of patients who received WCRT and PCRT, respectively. Median follow-up time was 18.4 months (range, 4-161 months). Forty-six patients (90.2%) experienced disease recurrence, most commonly at the parenchymal resection bed (76.5%). No patients experienced an isolated dural recurrence. The median PFS and OS for the PCRT and WCRT cohorts were 8.6 vs 10.8 months (P = .979) and 19.9 vs 18.6 months (P = .859), respectively. PCRT was associated with a lower RT dose to the brainstem, optic, and ocular structures, hippocampus, and pituitary. Conclusion We identified no isolated dural recurrence and similar PFS and OS regardless of postoperative RT volume, whereas PCRT was associated with dose reduction to critical structures. Omission of dural RT may be considered a reasonable alternative approach. Further validation with larger comparative studies is warranted.