Optimizing patient selection for stereotactic ablative radiotherapy in patients with locally advanced pancreatic cancer after initial chemotherapy - a single center prospective cohort

Background

The role of stereotactic ablative radiation therapy (SABR) as local treatment option after chemotherapy for locally advanced pancreatic cancer (LAPC) is evolving. However adequate patient selection criteria for SABR in patients with LAPC are lacking.

Methods

A prospective institutional database collected data of patients with LAPC treated with chemotherapy, mainly FOLFIRINOX, followed by SABR, which was delivered using magnetic resonance guided radiotherapy, 40 Gy in 5 fractions within two weeks. Primary endpoint was overall survival (OS). Cox regression analyses were performed to identify predictors for OS.

Results

Overall, 74 patients were included, median age 66 years, 45.9% had a KPS score of ≥90. Median OS was 19.6 months from diagnosis and 12.1 months from start of SABR. Local control was 90% at one year. Multivariable Cox regression analyses identified KPS ≥90, age <70, and absence of pain prior to SABR as independent favorable predictors for OS. The rate of grade ≥3 fatigue and late gastro-intestinal toxicity was 2.7%.

Conclusions

SABR is a well-tolerated treatment in patients with unresectable LAPC following chemotherapy, with better outcomes when applied in patients with higher performance score, age <70 years and absence of pain. Future randomized trials will have to confirm these findings.

Stereotactic ablative radiotherapy or best supportive care in patients with localized pancreatic cancer not receiving chemotherapy and surgery (PANCOSAR): a nationwide multicenter randomized controlled trial according to a TwiCs design

BACKGROUND

Significant comorbidities, advanced age, and a poor performance status prevent surgery and systemic treatment for many patients with localized (non-metastatic) pancreatic ductal adenocarcinoma (PDAC). These patients are currently treated with 'best supportive care'. Therefore, it is desirable to find a treatment option which could improve both disease control and quality of life in these patients. A brief course of high-dose high-precision radiotherapy i.e. stereotactic ablative body radiotherapy (SABR) may be feasible.

METHODS

A nationwide multicenter trial performed within a previously established large prospective cohort (the Dutch Pancreatic cancer project; PACAP) according to the 'Trial within cohorts' (TwiCs) design. Patients enrolled in the PACAP cohort routinely provide informed consent to answer quality of life questionnaires and to be randomized according to the TwiCs design when eligible for a study. Patients with localized PDAC who are unfit for chemotherapy and surgery or those who refrain from these treatments are eligible. Patients will be randomized between SABR (5 fractions of 8 Gy) with 'best supportive care' and 'best supportive care' only. The primary endpoint is overall survival from randomization. Secondary endpoints include preservation of quality of life (EORTC-QLQ-C30 and -PAN26), NRS pain score response and WHO performance scores at baseline, and, 3, 6 and 12 months. Acute and late toxicity will be scored using CTCAE criteria version 5.0: assessed at baseline, day of last fraction, at 3 and 6 weeks, and 3, 6 and 12 months following SABR.

DISCUSSION

The PANCOSAR trial studies the added value of SBRT as compared to 'best supportive care' in patients with localized PDAC who are medically unfit to receive chemotherapy and surgery, or refrain from these treatments. This study will assess whether SABR, in comparison to best supportive care, can relieve or delay tumor-related symptoms, enhance quality of life, and extend survival in these patients.

TRIAL REGISTRATION

Clinical trials, NCT05265663 , Registered March 3 2022, Retrospectively registered.

Meta-analysis comparing upfront surgery with neoadjuvant treatment in patients with resectable or borderline resectable pancreatic cancer

Background

Studies comparing upfront surgery with neoadjuvant treatment in pancreatic cancer may report only patients who underwent resection and so survival will be skewed. The aim of this study was to report survival by intention to treat in a comparison of upfront surgery versus neoadjuvant treatment in resectable or borderline resectable pancreatic cancer.

Methods

MEDLINE, Embase and the Cochrane Library were searched for studies reporting median overall survival by intention to treat in patients with resectable or borderline resectable pancreatic cancer treated with or without neoadjuvant treatment. Secondary outcomes included overall and R0 resection rate, pathological lymph node rate, reasons for unresectability and toxicity of neoadjuvant treatment.

Results

In total, 38 studies were included with 3484 patients, of whom 1738 (49·9 per cent) had neoadjuvant treatment. The weighted median overall survival by intention to treat was 18·8 months for neoadjuvant treatment and 14·8 months for upfront surgery; the difference was larger among patients whose tumours were resected (26·1 versus 15·0 months respectively). The overall resection rate was lower with neoadjuvant treatment than with upfront surgery (66·0 versus 81·3 per cent; P < 0·001), but the R0 rate was higher (86·8 (95 per cent c.i. 84·6 to 88·7) versus 66·9 (64·2 to 69·6) per cent; P < 0·001). Reported by intention to treat, the R0 rates were 58·0 and 54·9 per cent respectively (P = 0·088). The pathological lymph node rate was 43·8 per cent after neoadjuvant therapy and 64·8 per cent in the upfront surgery group (P < 0·001). Toxicity of at least grade III was reported in up to 64 per cent of the patients.

Conclusion

Neoadjuvant treatment appears to improve overall survival by intention to treat, despite lower overall resection rates for resectable or borderline resectable pancreatic cancer.

PROSPERO registration number: CRD42016049374.

Improved survival with neoadjuvant treatment

Definitive chemoradiation for locoregional recurrences of esophageal cancer after primary curative treatment

The aim of this study was to determine the outcome of salvage definitive chemoradiation (dCRT) for a locoregional recurrence after any prior curative treatment outside previously irradiated areas. Thirty-nine patients treated between January 2005 and December 2014 were reviewed for locoregional recurrent esophageal cancer outside previously irradiated areas. All patients received salvage treatment with external beam radiotherapy (50.4 Gy in 28 fractions) combined with weekly concurrent paclitaxel and carboplatin. The median follow-up period was 15 months (range 1.7-120). The median overall survival (OS) for all patients after salvage dCRT was 22 months (95% CI 6.2-37.6). The 1-, 3-, and 5-year OS was 72%, 31%, and 28%, respectively. Median survival after salvage dCRT for a regional lymph node recurrence was 33 months (95% CI 5.8-60.3) versus 14 months (95% CI 6.8-21.6) for a recurrence at the anastomosis (P = 0.022, logrank). Median OS was 35 months for the squamous cell carcinoma group and 19 months for the adenocarcinoma group (P = 0.67). Sixteen of 39 patients developed a locoregional recurrence after salvaged dCRT. The median locoregional recurrence-free survival (LRFS) was 24 months. The 1-, 3-, and 5-year LRFS was 79%, 36%, and 36%, respectively. Median disease-free survival (DFS) was 15 months. The 1-, 3-, and 5-year DFS was 66%, 27%, and 27%, respectively. Of 16 patients, 8 (50%) with a primary failure at the site of the anastomosis developed a local recurrence after salvaged dCRT compared to 7 of 22 patients (32%) with a primary recurrence in a lymph node. Definitive chemoradiation is a feasible and effective treatment for locoregional recurrent esophageal cancer outside a previously irradiated area, and should be given with a curative intent. This holds true for recurrence of both squamous cell carcinoma and adenocarcinoma. Lymph node recurrences have a markedly better prognosis than recurrences at the site of the anastomosis.

Definitive chemoradiation for patients with inoperable and/or unresectable esophageal cancer: locoregional recurrence pattern

A locoregional recurrence after definitive chemoradiation (dCRT) for patients with inoperable or unresectable esophageal cancer occurs in about 50% of the patients and is a major cause of failure with a poor prognosis. The aim of this study was to determine the pattern of locoregional recurrence and its prognostic factors after dCRT in order to search for improvements in radiation treatment. We retrospectively reviewed 184 patients treated with external beam radiotherapy (50.4 Gray/28 fractions), combined with weekly concurrent paclitaxel and carboplatin. Locoregional recurrences were defined by clinical signs of recurrent or progressive disease, combined with progression on computed tomography/positron emission tomography-computed tomography scan, or suspicious endoscopic findings and/or histological proof of recurrence. The site of locoregional recurrence was analyzed with respect to the borders of the radiation fields. After a mean follow up of 22.8 months, 76 patients (41%) had evidence of locoregional recurrence. The 3-years locoregional recurrence-free rate was 45%. The majority of locoregional recurrences occurred within 12 months, nearly all within 24 months. The majority of these patients failed at the site of the primary tumor (86%). Infield locoregional recurrences at the site of the lymph nodes only occurred in 1% compared with 57% at the site of the primary tumor only. Outfield locoregional lymph node recurrences occurred in 22%, without infield recurrence occurred in only 4% of all patients. The 1-, 3-, and 5-year overall survival was 65%, 28%, and 21%, respectively. The current analysis demonstrates that a locoregional recurrence after dCRT occurs in 41% of the patients, the majority at the site of the primary tumor. These data suggest a benefit of dose intensification of the primary tumor, but not at the site of the lymph nodes. Higher radiation doses should be assessed with prospective trials.