Concurrent Chemoradiotherapy Versus Chemotherapy Alone for Unresectable Locally Advanced Pancreatic Cancer: A Retrospective Cohort Study

Dose-escalated SBRT for borderline and locally advanced pancreatic cancer. Feasibility, safety and preliminary clinical results of a multicenter study

Background

Pancreatic Stereotactic Body Radiotherapy (SBRT) allows for the administration of a higher biologically effective doses (BED), that would be essential to achieve durable tumor control. Escalating treatment doses need a very accurate tumor positioning and motion control during radiotherapy.The aim of this study to assess the feasibility and safety of a Simultaneous Integrated Boost (SIB) dose-escalated protocol at 45 Gy, 50 Gy and 55 Gy in 5 consecutive daily fractions, in Border Line Resectable Pancreatic Cancer (BRCP) /Locally Advanced Pancreatic Cancer (LAPC) by means of a standard LINAC platform.

Methods

Patients diagnosed of BRPC/LAPC, candidates for neoadjuvant chemotherapy and SBRT, in four university hospitals of the province of Las Palmas (Canary Islands, Spain) were included in this prospective study. Radiotherapy was administered using standard technology (LINACS) with advanced positioning (Lipiodol® and metallic stent used as fiducial markers) and tumor motion control (4D, DBH, Calypso®). There were 3 planned dose-escalated SIB groups, 45 Gy/5f (9 patients) 50 Gy/5f (9 + 9 patients) and 55 Gy/5f (9 patients). The defined primary end points of the study were the safety and feasibility of the proposed treatment protocol. Secondary endpoints included radiological tumor response after SBRT, local control and survival.

Results

From June 2017 to December 2022, sixty-two patients were initially assessed for eligibility in the study in the four participating centers, and 49 were candidates for chemotherapy (CHT). Forty-one were referred to radiotherapy after CHT and 33 finally were treated by escalated-dose SIB, 45 Gy (9 patients) 50 Gy (16 patients), 55 Gy(8 patients). All patients completed the scheduled treatment and no acute or late severe (≥grade3) gastrointestinal toxicity was observed.Local response was analyzed by CT/MRI two months after the end of SBRT. Ten patients (31,25 %) achieved objective response (2/9:45 Gy, 5/15:50 Gy, 3/8:55 Gy). Follow-up was closed as July 2023. Freedom from local progression at 1-2y were 89,3% (95 %CI:83,4-95,2%) and 66 % (95 %CI:54,6-77,4%) respectively. The 1-2y survival rates were 95,7% (95 %CI:91,4-100 % and 48,6% (95 %CI:37,7-59,5%) respectively.

Conclusion

These promising results should be confirmed by further studies with larger sample size and extended follow-up period.

Concurrent Nab-paclitaxel and Radiotherapy: Novel Radiosensitization for Borderline Resectable or Unresectable Pancreatic Cancer

PURPOSE

This study evaluates the toxicity and tumor response with concurrent nab-paclitaxel chemoradiotherapy (CRT) compared with standard (5-fluorouracil or gemcitabine) CRT.

MATERIALS AND METHODS

Fifty patients with borderline resectable or unresectable pancreatic adenocarcinoma from 2014 to 2017 were divided into 2 groups: concurrent nab-paclitaxel (100 to 125 mg/m2 weekly) CRT (median: 2.1 Gy fraction size and 52.5 Gy total) or standard CRT (median: 1.8 Gy fraction size, 54.5 Gy total). The primary endpoint was toxicity, and secondary endpoints were local failure and conversion to resectability. Comparisons were made using rank-sum or Fisher exact test and multivariable competing risk regression for the cumulative incidence of local failure.

RESULTS

There were 28 patients in the nab-paclitaxel CRT group and 22 in the standard CRT group; 88% had the unresectable disease. The median follow-up was 18 months. The median duration of chemotherapy before concurrent CRT was 1.9 and 2.3 months in the nab-paclitaxel and standard CRT groups (P=0.337), and radiotherapy dose was 52.5 Gy (range, 52.5 to 59.4 Gy) and 54.5 Gy (range, 45.0 to 59.4 Gy), respectively. There were no statistically significant grade ≥2 toxicities. The nab-paclitaxel CRT group experienced a nonstatistically significant lower incidence of local failure (hazard ratio=0.91, 95% confidence interval: 0.27-3.03, P=0.536). More patients in the nab-paclitaxel CRT group proceeded to surgery (9/28 compared with 3/22 in the standard CRT, P=0.186); of which 6 (25%) in the nab-paclitaxel CRT and 2 (10%) in the standard CRT groups were initially unresectable.

CONCLUSIONS

Nab-paclitaxel CRT had similar toxicity compared with standard CRT in the treatment of borderline resectable or unresectable pancreatic cancer. Its use was associated with an arithmetically lower cumulative incidence of local failure and an arithmetically higher conversion to resectability, both of which were not statistically significant.

Therapeutic Co-targeting of WEE1 and ATM Downregulates PD-L1 Expression in Pancreatic Cancer

PURPOSE

Pancreatic cancer (PC) is one of the most lethal cancers worldwide, but there are currently no effective treatments. The DNA damage response (DDR) is under investigation for the development of novel anti-cancer drugs. Since DNA repair pathway alterations have been found frequently in PC, the purpose of this study was to test the DDR-targeting strategy in PC using WEE1 and ATM inhibitors.

Materials and Methods

We performed in vitro experiments using a total of ten human PC cell lines to evaluate antitumor effect of AZD1775 (WEE1 inhibitor) alone or combination with AZD0156 (ATM inhibitor). We established Capan-1-mouse model for in vivo experiments to confirm our findings.

RESULTS

In our research, we found that WEE1 inhibitor (AZD1775) as single agent showed anti-tumor effects in PC cells, however, targeting WEE1 upregulated p-ATM level. Here, we observed that co-targeting of WEE1 and ATM acted synergistically to reduce cell proliferation and migration, and to induce DNA damage in vitro. Notably, inhibition of WEE1 or WEE1/ATM downregulated programmed cell death ligand 1 expression by blocking glycogen synthase kinase-3β serine 9 phosphorylation and decrease of CMTM6 expression. In Capan-1 mouse xenograft model, AZD1775 plus AZD0156 (ATM inhibitor) treatment reduced tumor growth and downregulated tumor expression of programmed cell death ligand 1, CMTM6, CD163, and CXCR2, all of which contribute to tumor immune evasion.

CONCLUSION

Dual blockade of WEE1 and ATM might be a potential therapeutic strategy for PC. Taken toget.

Survival benefit of conversion surgery for patients with initially unresectable pancreatic cancer who responded favorably to nonsurgical treatment

BACKGROUND

Conversion surgery (CS) is expected as a new therapeutic strategy for patients with unresectable pancreatic cancer (UR-PC). We analyzed outcomes of CS for patients with UR-PC and evaluated the survival benefit of CS.

METHODS

Thirty-four patients diagnosed with UR-PC according to the National Comprehensive Cancer Network guideline underwent CS in our hospital. Resectability was considered by multimodal images in patients who underwent nonsurgical treatment (NST) for more than 6 months. CS was performed only in patients who were judged to be able to undergo R0 resection.

RESULTS

Twenty-six patients had locally advanced PC, and eight had distant metastases. The median duration of NST was 9 (range 5-44) months. R0 resection was achieved in 30 patients (88.2%). Six patients (17.6%) showed Evans grade ≥III. Three- and 5-year overall survival (OS) rates from initial treatment were 74% and 56.9%, respectively, with median survival time (MST) of 5.3 years. The actual 5-year OS rate in 19 patients was 47.4% with an MST of 4.0 years. Patients with Evans grade ≥III had a better prognosis than those with Evans grade <III (P = 0.0092, log-rank test).

CONCLUSIONS

Conversion surgery might have survival benefits to patients with UR-PC who responded favorably to NST.

Risk factors of liver metastasis from advanced pancreatic adenocarcinoma: a large multicenter cohort study

BACKGROUND

Clinical prognostic parameters of liver metastasis from pancreatic adenocarcinoma have not been specifically identified.This study is to explore the risk factors of liver metastasis in advanced pancreatic adenocarcinoma (PDAC) patients in China.

METHODS

A multicenter cohort study was conducted to explore whether liver metastasis in locally advanced and metastatic PDAC could be reflected by some common laboratory indexes. We collected 1787 advanced PDAC patients from three participating hospitals between 2004 and 2014. The associations between some laboratory indexes and risks of liver metastases were analyzed.

RESULTS

Results have shown that 87% of stage IV patients developed synchronous liver metastasis. Primary tumor location (body/tail vs. head/neck, OR 0.55, 95% CI 0.36-0.83), primary tumor diameter (≥20 mm vs. <20 mm, OR 1.77, 95% CI 1.16-2.70), elevated ALT and AST (OR 1.62, 95% CI 0.92-2.83), and elevated CA19-9 (OR 2.72, 95% CI 1.85-3.99) upon diagnosis are significantly associated with risk of synchronous liver metastasis. Among stage III patients, 30.1% developed metachronous liver metastasis. However, no risk factors were identified among these patients.

CONCLUSIONS

Primary tumor location, diameter, elevated ALT and AST, and increased CA19-9 are independent risk factors of synchronous liver metastasis in PDAC patients.

Change in carbohydrate antigen 19-9 level as a prognostic marker of overall survival in locally advanced pancreatic cancer treated with concurrent chemoradiotherapy

PURPOSE

To investigate the significance of carbohydrate antigen 19-9 (CA19-9) levels for survival in locally advanced pancreatic cancer (LAPC) treated with concurrent chemoradiotherapy (CCRT).

METHODS/PATIENTS

We retrospectively reviewed data from 97 LAPC patients treated with CCRT between 2000 and 2013. CA19-9 levels (initial and post-CCRT) and their changes [{(post-CCRT CA19-9 level - initial CA19-9 level)/(initial CA19-9 level)} × 100] were analyzed for overall survival. A cut-off point of 37 U/mL was used to analyze initial and post-CCRT CA19-9 levels. In order to define an optimal cut-off point for change in CA19-9 level, the maxstat package of R was applied.

RESULTS

Median overall survival was 14.7 months (95% CI 13.4-16.0), and the 2-year survival rate was 16.5%. The estimated optimal cut-off point of CA19-9 level change was 94.4%. On univariate analyses, CA19-9 level change between initial and post-CCRT was significantly correlated with overall survival (median survival time 9.7 vs 16.3 months, p < 0.001). Multivariate analyses confirmed that CA19-9 level change from initial to post-CCRT was the only prognostic factor (p < 0.001).

CONCLUSIONS

Change in CA19-9 level between initial and post-CCRT was a significant prognostic marker for overall survival in LAPC treated with CCRT. A CA19-9 level increase >94.4% might serve as a surrogate marker for poor survival in patients with LAPC undergoing CCRT, and the prognostic power surpassed other CA19-9 variables including initial and post-CCRT values.

Risk factors for latent distant organ metastasis detected by staging laparoscopy in patients with radiologically defined locally advanced pancreatic ductal adenocarcinoma

OBJECTIVES

We aimed to identify risk factors for latent distant organ metastasis in patients with radiographically defined locally advanced (RDLA) pancreatic ductal adenocarcinoma (PDAC).

METHODS

RDLA disease was defined as unresectable disease without distant organ metastasis based on resectability status by NCCN guidelines. Between January 2005 and November 2015, 110 consecutive patients underwent staging laparoscopy to rule out latent distant metastasis. Univariate and multivariate analyses were performed to identify risk factors for latent distant organ metastasis or peritoneal metastasis (PM), defined as peritoneal dissemination and/or positive peritoneal lavage cytology (PPC).

RESULTS

Latent distant organ metastasis was diagnosed by staging laparoscopy in 62 patients. PPC was found in 23%, peritoneal dissemination in 19%, and liver metastasis in 15%. Univariate analysis showed tumor location, preoperative CA 19-9 level and tumor size, and multivariate analysis revealed tumor size >55 mm and CA 19-9 level >60 IU/ml as risk factors for latent distant metastasis. Multivariate analysis showed pancreas body-tail tumors and tumor size >42 mm as risk factors for PM; 65.4% of pancreas body-tail tumors >42 mm had PM.

CONCLUSIONS

Patients with large pancreas body-tail tumors and high CA 19-9 level are at greater risk for latent distant organ metastasis or PM, and should undergo staging laparoscopy routinely for accurate diagnosis (UMIN000023125).