Prognostic Factors for Elderly Patients Treated With Stereotactic Body Radiation Therapy for Pancreatic Adenocarcinoma

Stereotactic body radiotherapy for pancreatic cancer - A systematic review of prospective data

Purpose

This systematic review aims to comprehensively summarize the current prospective evidence regarding Stereotactic Body Radiotherapy (SBRT) in various clinical contexts for pancreatic cancer including its use as neoadjuvant therapy for borderline resectable pancreatic cancer (BRPC), induction therapy for locally advanced pancreatic cancer (LAPC), salvage therapy for isolated local recurrence (ILR), adjuvant therapy after radical resection, and as a palliative treatment. Special attention is given to the application of magnetic resonance-guided radiotherapy (MRgRT).

Methods

Following PRISMA guidelines, a systematic review of the Medline database via PubMed was conducted focusing on prospective studies published within the past decade. Data were extracted concerning study characteristics, outcome measures, toxicity profiles, SBRT dosage and fractionation regimens, as well as additional systemic therapies.

Results and conclusion

31 studies with in total 1,571 patients were included in this review encompassing 14 studies for LAPC, 9 for neoadjuvant treatment, 2 for adjuvant treatment, 2 for ILR, with an additional 4 studies evaluating MRgRT. In LAPC, SBRT demonstrates encouraging results, characterized by favorable local control rates. Several studies even report conversion to resectable disease with substantial resection rates reaching 39%. The adoption of MRgRT may provide a solution to the challenge to deliver ablative doses while minimizing severe toxicities. In BRPC, select prospective studies combining preoperative ablative-dose SBRT with modern induction systemic therapies have achieved remarkable resection rates of up to 80%. MRgRT also holds potential in this context. Adjuvant SBRT does not appear to confer relevant advantages over chemotherapy. While prospective data for SBRT in ILR and for palliative pain relief are limited, they corroborate positive findings from retrospective studies.

Survival benefits and disparities in radiation therapy for elderly patients with pancreatic ductal adenocarcinoma

BACKGROUND

Older patients represent a unique subgroup of the cancer patient population, for which the role of cancer therapy requires special consideration. However, the outcomes of radiation therapy (RT) in elderly patients with pancreatic ductal adenocarcinoma (PDAC) are not well-defined in the literature.

AIM

To explore the use and effectiveness of RT in the treatment of elderly patients with PDAC in clinical practice.

METHODS

Data from patients with PDAC aged ≥ 65 years between 2004 and 2018 were collected from the Surveillance, Epidemiology, and End Results database. Multivariate logistic regression analysis was performed to determine factors associated with RT administration. Overall survival (OS) and cancer-specific survival (CSS) were evaluated using the Kaplan–Meier method with the log-rank test. Univariate and multivariate analyses with the Cox proportional hazards model were used to identify prognostic factors for OS. Propensity score matching (PSM) was applied to balance the baseline characteristics between the RT and non-RT groups. Subgroup analyses were performed based on clinical characteristics.

RESULTS

A total of 12245 patients met the inclusion criteria, of whom 2551 (20.8%) were treated with RT and 9694 (79.2%) were not. The odds of receiving RT increased with younger age, diagnosis in an earlier period, primary site in the head, localized disease, greater tumor size, and receiving chemotherapy (all P < 0.05). Before PSM, the RT group had better outcomes than did the non-RT group [median OS, 14.0 vs 6.0 mo; hazard ratio (HR) for OS: 0.862, 95% confidence interval (CI): 0.819–0.908, P < 0.001; and HR for CSS: 0.867, 95%CI: 0.823–0.914, P < 0.001]. After PSM, the survival benefit associated with RT remained comparable (median OS: 14.0 vs 11.0 mo; HR for OS: 0.818, 95%CI: 0.768–0.872, P < 0.001; and HR for CSS: 0.816, 95%CI: 0.765–0.871, P < 0.001). Subgroup analysis revealed that the survival benefits (OS and CSS) of RT were more significant in patients aged 65 to 80 years, in regional and distant stages, with no surgery, and receiving chemotherapy.

CONCLUSION

RT improved the outcome of elderly patients with PDAC, particularly those aged 65 to 80 years, in regional and distant stages, with no surgery, and who received chemotherapy. Further prospective studies are warranted to validate our results.

Multi-Institutional Outcomes of Patients Aged 75 years and Older With Pancreatic Ductal Adenocarcinoma Treated With 5-Fraction Ablative Stereotactic Magnetic Resonance Image-Guided Adaptive Radiation Therapy (A-SMART)

PURPOSE

Treatment options for pancreatic ductal adenocarcinoma (PDAC) are commonly limited for patients with advanced age due to medical comorbidities and/or poor performance status. These patients may not be candidates for more aggressive chemotherapy regimens and/or surgical resection leaving few, if any, other effective treatments. Ablative stereotactic MRI-guided adaptive radiation therapy (A-SMART) is both efficacious and safe for PDAC and can achieve excellent long-term local control, however, the appropriateness of A-SMART for elderly patients with inoperable PDAC is not well understood.

METHODS

A retrospective analysis was performed of inoperable non-metastatic PDAC patients aged 75 years or older treated on the MRIdian Linac at 2 institutions. Clinical outcomes of interest included overall survival (OS), progression-free survival (PFS), distant metastasis-free survival (DMFS), and locoregional (LRC). Toxicity was graded according to Common Terminology Criteria for Adverse Events (CTCAE, v5).

RESULTS

A total of 49 patients were evaluated with a median age of 81 years (range, 75-91) and a median follow-up of 14 months from diagnosis. PDAC was classified as locally advanced (46.9%), borderline resectable (36.7%), or medically inoperable (16.3%). Neoadjuvant chemotherapy was delivered to 84% of patients and all received A-SMART to a median 50 Gy (range, 40-50 Gy) in 5 fractions. 1 Year LRC, PFS, and OS were 88.9%, 53.8%, and 78.9%, respectively. Nine patients (18%) had resection after A-SMART and benefited from PFS improvement (26 vs 6 months, P = .01). ECOG PS <2 was the only predictor of improved OS on multivariate analysis. Acute and late grade 3 + toxicity rates were 8.2% and 4.1%, respectively.

CONCLUSIONS

A-SMART is associated with encouraging LRC and OS in elderly patients with initially inoperable PDAC. This novel non-invasive treatment strategy appears to be well-tolerated in patients with advanced age and should be considered in this population that has limited treatment options.

Long-term outcomes of octogenarian pancreatic cancer patients treated with carbon ion radiotherapy

BACKGROUND

Pancreatic cancer is a disease of the elderly; patients >65 years are 60% of the cases. Due to multiple comorbidities, treating these patients is challenging. We report the efficacy and safety of carbon ion radiotherapy (C-ion RT) in octogenarians.

METHODS

We retrospectively analyzed the cases of 46 pancreatic cancer patients aged ≥80 years (median 83, range 80-97) treated with definitive C-ion RT in 2007-2018 at our institute.

RESULTS

Twenty-five patients (54%) had resectable or borderline-resectable disease; none underwent surgery (because of medical reasons, e.g., age, multiple comorbidities). C-ion RT was delivered with a median dose of 55.2 Gy (RBE) in 12 fractions. The survivors' median follow-up period was 43 (range 19-76) months. The entire cohort's median overall survival (OS) was 15 (95%CI: 14-22) months with a 3-year OS of 20% (95%CI: 11%-35%). On both univariate and multivariate analyses, baseline CA19-9 remained the significant independent OS prognostic factor (p = 0.032). The 3-year local control rate for all patients was 34% (95%CI: 19%-53%). Local failure (n = 25, 54%) was as common as distant relapse (n = 26, 57%); 33% of the patients experienced both local and systemic failure. About 15% underwent re-C-ion RT for infield recurrence; they achieved a median 22-month OS. No patients exhibited grade ≥3 severe acute or late toxicities (including those who received re-C-ion RT).

CONCLUSIONS

C-ion RT in octogenarians with pancreatic cancer showed promising outcomes with acceptable acute and late toxicities and can be considered a reasonable alternative to radical surgery.

Upfront Chemotherapy Followed by Stereotactic Body Radiation Therapy with or without Surgery in Older Patients with Localized Pancreatic Cancer: A Single Institution Experience and Review of the Literature

OBJECTIVE

To report on clinical outcomes and toxicity in older (age ≥ 70 years) patients with localized pancreatic cancer treated with upfront chemotherapy followed by stereotactic body radiation therapy (SBRT) with or without surgery.

METHODS

Endpoints included overall survival (OS), local progression-free survival (LPFS), distant metastasis-free survival (DMFS), progression-free survival (PFS), and toxicity.

RESULTS

A total of 57 older patients were included in the study. Median OS was 19.6 months, with six-month, one-year, and two-year OS rates of 83.4, 66.5, and 42.4%. On MVA, resection status (HR: 0.30, 95% CI 0.12-0.91, p = 0.031) was associated with OS. Patients with surgically resected tumors had improved median OS (29.1 vs. 7.0 months, p < 0.001). On MVA, resection status (HR: 0.40, 95% CI 0.17-0.93, p = 0.034) was also associated with PFS. Patients with surgically resected tumors had improved median PFS (12.9 vs. 1.6 months, p < 0.001). There were 3/57 cases (5.3%) of late grade 3 radiation toxicity and 2/38 cases (5.3%) of Clavien-Dindo grade 3b toxicity in those who underwent resection.

CONCLUSION

Multimodality therapy involving SBRT is safe and feasible in older patients with localized pancreatic cancer. Surgical resection was associated with improved clinical outcomes. As such, older patients who complete chemotherapy should not be excluded from aggressive local therapy when possible.

New Potential Options for SBRT in Pancreatic Cancer

Stereotactic body radiotherapy (SBRT) is an emerging treatment option for patients with pancreatic cancer, as it can provide a therapeutic benefit with significant advantages for patients' quality of life over standard conventional chemoradiation (CRT). The objective of this review is to present alternative clinical settings in which SBRT may benefit patients with pancreatic cancer. These include palliation of pain, elderly patients who are not surgical candidates, local therapy in oligometastatic cases and salvaging local failures after surgery or external beam radiation. We will review these individually and provide supporting literature for each.

The Role of Radiation Therapy in the Older Patient

PURPOSE OF REVIEW

Older patients represent a unique subgroup of the cancer patient population for which the role of radiation therapy (RT) requires special consideration. This review will discuss many of these considerations as well as various radiation treatment techniques in the context of a variety of disease sites.

RECENT FINDINGS

Several recent studies give insight into the management of older cancer patients considering their age, performance status, comorbid conditions, quality of life, genetics, cost, and individual goals. RT plays an evolving and pivotal role in providing optimal care for this population. Recent advances in RT technique allow for more precise treatment delivery and reduced toxicity. Studies evaluating the use of radiation therapy in breast, brain, lung, prostate, rectal, pancreatic, esophageal, and oligometastatic cancer are summarized and discussed in the context of treating the older patient population. Individual age, performance and functional status, comorbid conditions, and patients' objectives and goals should all be considered when presenting treatment options for older patients and age alone should not disqualify patients from curative intent treatments. When possible, hypofractionated courses should be utilized as outcomes are often equivalent and toxicities are reduced. In many cases, RT may be preferable to other treatment options due to decreased toxicity profile and acceptable disease control.

Clinical outcomes and prognostic factors of stereotactic body radiation therapy combined with gemcitabine plus capecitabine for locally advanced unresectable pancreatic cancer

PURPOSE

This study aimed to evaluate the clinical outcomes, toxicity, and prognostic factors of SBRT combined with gemcitabine plus capecitabine (GEM-CAP) in treating locally advanced pancreatic cancer (LAPC).

METHODS

A total of 56 patients with LAPC treated with SBRT combined with GEM-CAP were reviewed from October 2010 to October 2016. The median total prescription dose at five fractions was 40 Gy (30-50 Gy). The patients were subjected to two cycles of GEM-CAP before SBRT. GEM-CAP chemotherapy was then offered for four cycles or until disease tolerance or progression. The primary endpoints included overall survival (OS) and progression-free survival (PFS).

RESULTS

The median OS and PFS from the date of diagnosis was 19 (95% CI 14.6-23.4) and 12 months (95% CI 8.34-15.66), respectively. The 1-year and 2-year survival rates were 82.1% and 35.7%, whereas the 1-year and 2-year PFS rates were 48.2% and 14.3%, respectively. The median carbohydrate antigen 19-9-determined PFS time was 11 months (95% CI 5.77-16.24). Multivariate analysis demonstrated that tumor diameter, lymph node metastasis, pre-treatment CA19-9 level, and post-treatment CA19-9 decline were independent prognostic factors (p < 0.05). Acute toxicity was minimal, with two cases (3.6%) experiencing grade 3 duodenal obstruction. No adverse events greater than grade 3 occurred. In late toxicity, three patients (5.4%) developed grade 3 gastrointestinal toxicity and two (3.6%) suffered from perforation caused by grade 4 radiation enteritis and intestinal fistula.

CONCLUSIONS

The combination of Cyberknife SBRT and GEM-CAP achieved excellent efficacy with acceptable toxicity for LAPC.