Palliative radiation therapy in patients with metastasized pancreatic cancer - description of a rare patient group

Metastatic Pancreatic Cancer: Where Are We?

Pancreatic cancer is one of the most lethal neoplasms worldwide; it is aggressive in nature and has a poor prognosis. The overall survival rate for pancreatic cancer is low. Most patients present non-specific symptoms in the advanced stages, which generally leads to late diagnosis, at which point there is no option for curative surgery. The treatment of metastatic pancreatic cancer includes systemic therapy, in some cases radiotherapy, and more recently, molecular targeted therapies, which can positively impact cancer control and improve quality of life. This review provides an overview of the molecular landscape of pancreatic cancer based on the most recent literature, as well as current treatment options for patients with metastatic pancreatic cancer.

Palliative Therapies in Metastatic Pancreatic Cancer: Does Medicaid Expansion Make a Difference?

BACKGROUND

The aim of this study was to evaluate the impact of medicaid expansion (ME) on receipt of palliative therapies in metastatic pancreatic cancer patients.

PATIENTS AND METHODS

A difference-in-differences (DID) approach was used to analyze patients with metastatic pancreatic cancer identified from the National Cancer Database diagnosed during two time periods: pre-expansion (2010-2012) and post-expansion (2014-2016). Patients diagnosed while residing in ME states were compared with those in non-ME states. Multivariable logistic regression was used to identify predictors of receipt of palliative therapies.

RESULTS

Of 87,738 patients overall, 7483(18.1%) received palliative therapies in the pre-expansion, while 10,211(21.5%) received palliative therapies in the post-expansion period. In the pre-expansion period, treatment at a high-volume facility (HVF) (odds ratio [OR] 1.10, 95% confidence interval [CI] 1.02-1.18) and non-west geographic location were predictive of increased palliative therapies. In the post-expansion period, treatment at an HVF (OR 1.09, 95% CI 1.02-1.16), geographic location, and living in an ME state at the time of diagnosis (OR 1.14, 95% CI 1.06-1.22) were predictive of increased palliative therapies. Older age, highest quartile median income (zip-code based), and treatment at a nonacademic facility were independently associated with decreased palliative therapies in both periods. DID analysis demonstrated that patients with metastatic pancreatic cancer living in ME states had increased receipt of palliative therapies relative to those in non-ME states (DID = 2.68, p < 0.001).

CONCLUSIONS

The overall utilization of palliative therapies in metastatic pancreatic cancer is low. Multiple sociodemographic disparities exist in the receipt of palliative therapies. ME is associated with increased receipt of palliative therapies in patients with metastatic pancreatic cancer.

The survival impact of palliative radiotherapy on synchronous metastatic pancreatic ductal adenocarcinoma: metastatic site can serve for radiotherapy-decision

Background: The metastatic site seems to represent a malignancy with a different biological characteristic and is an important prognostic factor in metastatic pancreatic ductal adenocarcinoma (mPDAC). Palliative radiotherapy is a therapeutic option, and usually used for pain management in the treatment of mPDAC. The real-world effect of radiotherapy on the survival outcomes of mPDAC patients might do exist and is worth exploring.

Methods: Data from the Surveillance, Epidemiology, and End Results (SEER) was extracted to identify mPDAC diagnosed in the periods of 2010-2016. The statistical methods included Pearson's chi-square test, Log-rank test, Cox regression model and propensity score matching (PSM).

Results: Radiotherapy was able to improve the overall survival of PDAC with liver metastasis (p<0.001), but not for PDAC patients with lung (p=0.130), bone (p=0.451) and brain metastasis (p=0.226) before PSM. Radiotherapy can only a prognostic factor for PDAC liver metastasis (p=0.001) in the cox regression analysis. The survival curves provided consistent results with cox regression analysis (PDAC with liver metastasis: p=0.023, PDAC with lung metastasis: p=0.528, PDAC with bone metastasis: p=0.210, PDAC with brain metastasis: p=0.106) after PSM. We continue to divided PDAC liver patients into PDAC-liver-metastasis with and without lung, bone, and/or brain (LBB) metastasis. Finally, radiotherapy can be used as a feasible treatment to prolong the overall survival of patients with PDAC liver metastasis without LBB metastasis.

Conclusions: Radiotherapy can be used as a feasible treatment to prolong the overall survival of patients with PDAC liver metastasis without LBB metastasis.

Prognostic value and impact of cerebral metastases in pancreatic cancer

Background: Pancreatic cancer is a fatal disease most often diagnosed at an advanced stage. Most patients already suffer from irresectable tumor or distant metastases being most commonly found in the liver or the lung. However, cerebral metastases occur extremely rare.Methods: We performed a retrospective analysis of our database to identify all patients diagnosed with pancreatic cancer and cerebral metastases who underwent surgical treatment in our department from January 2004 to November 2016.Results: Only 0.2% (4 of 2492) were diagnosed with cerebral metastases. Two patients had surgical resection of the cerebral metastases. One patient underwent palliative radiation therapy and the fourth patient received only palliative therapy. Mean interval between initial diagnosis and development of brain metastases was 8.5 months (range 1-20). Mean survival period after diagnosis of brain metastases was 4.75 months (range 1-10).Conclusions: Cerebral metastases of pancreatic cancer occur extremely rare. They are associated with an advanced tumor stage, commonly liver and lung metastases. All patients presenting with neurological symptoms, multifocal metastases, and significantly elevated CA 19-9 levels are suspicious of sustaining cerebral metastases and should undergo brain imaging.

An Approach to Identify Delivery of Palliative Radiation Therapy Using Health Care Claims Data: A Proof-of-Concept Application of a Visual Analytics Tool

PURPOSE

There is limited information on the use of data visualization tools for health services research applications. We provide a proof-of-concept application that focuses on claims-based measures of palliative radiation therapy. We investigate whether a guided, data-driven investigation contributes information for subsequent statistical analysis and algorithm development.

METHODS

This retrospective cohort study used linked registry and claims data on men who were diagnosed with stage IV M0 or stage IV M1b prostate cancer between 2005 and 2009, with associated claims from 2005 through 2010, and receiving radiation therapy. Preprocessing of data was accomplished by using EventFlow software to investigate longitudinal patterns in claims for radiation therapy in the 13 months after cancer diagnosis. Guided by results from EventFlow, we developed descriptive statistics to investigate the length of radiation therapy, use of bone metastasis coding, and mortality between M1b and M0 patients.

RESULTS

A total of 1,151 patients met the inclusion criteria. Taking advantage of the novel aggregation capability of EventFlow, we observed differences in the length of radiation therapy and the use of bone metastasis coding between men with (M1b) and without (M0) a diagnosis of bone metastasis. Seventy-nine percent of M1b patients received radiation for a duration ≤ 4 weeks, which suggested palliative radiation (to the bone). Seventy-six percent of M0 patients received radiation for ≥ 6 weeks, which suggested radiation to the prostate. Mortality was higher among those who received a shorter duration of radiation therapy compared with those who received a longer duration of therapy.

CONCLUSION

Use of EventFlow, followed by statistical analysis of the linked registry and claims data, identified useful components of a claims-based measure of radiation to the bone.

Bone metastasis as primary presentation of pancreatic ductal adenocarcinoma: A case report and literature review

PDAC bone metastases represent a clinical challenge characterized by multifaceted biological entity.

Utilization and trends in palliative therapy for stage IV pancreatic adenocarcinoma patients: a U.S. population-based study

BACKGROUND

Pancreatic adenocarcinoma is an aggressive malignancy, with most patients diagnosed with advanced or metastatic disease. Palliative therapies comprise an important, but underutilized, aspect of care. This aim of this study was to characterize the trends, factors, and outcomes associated with utilization of palliative therapies.

METHODS

Patients with stage IV pancreatic adenocarcinoma from the 2003-2011 U.S. National Cancer Database were identified and stratified by receipt of palliative therapy. Linear regression, multivariable logistic regression, and survival analyses using multivariate proportional hazards models were performed.

RESULTS

Sixty-eight thousand and seventy-five patients with stage IV disease were identified, of which only 11,449 (16.8%) underwent designated palliative therapy. The majority received systemic chemotherapy (37.2%), followed by surgery (19.0%), pain management alone (15.3%), radiation (8.1%), referral alone (11.7%), or a combination thereof (8.7%). Utilization of palliative therapies increased from 12.9% in 2003 to 19.2% in 2011 (P<0.001). Patients were less likely to undergo palliation when older than 60 (OR 0.89, P<0.001), or of black or Hispanic race (OR 0.83, P<0.001; OR 0.80, P<0.001, respectively, vs. Caucasians). Presence of comorbidities increased the use of palliative therapy (OR 1.16 per comorbidity, P<0.001). Survival was improved in those receiving palliative systemic chemotherapy (HR 0.55, P<0.001) and palliative surgery (HR 0.94, P<0.001), although this may be due to selection bias.

CONCLUSIONS

Despite the continued dismal prognosis of pancreatic cancer, palliation of symptoms remains underutilized in this country, particularly in non-Caucasian, older patients. Increased awareness of palliative options may help increase its utilization.

Skeletal-related events and mortality among men diagnosed with advanced prostate cancer: The impact of alternative measures of radiation to the bone

PURPOSE/OBJECTIVE(S)

Skeletal-related events (SREs), which include radiation to the bone (RtB), can occur among patients with bone metastasis (BM). There is a recognized potential for misclassification of RtB when using claims data. We compared alternative measures of RtB to better understand their impact on SRE prevalence and SRE-related mortality.

METHODS AND MATERIALS

We analyzed data for stage IV prostate cancer (PCa) cases identified between 2005 and 2009 in the Surveillance, Epidemiology, and End Results registry linked with Medicare claims. We created two measures of RtB: 1) a literature-based measure requiring the presence of a prior claim with a BM code; 2) a new measure requiring either that the BM code coincided with the radiation episode or that the duration of the radiation episode was less than or equal to 4 weeks. We estimated adjusted hazard ratios of an SRE using both measures among stratified samples: no metastasis (M0), metastasis to bone (M1b) and other sites (M1c).

RESULTS

The study sample included 5,074 men with stage IV PCa (median age 77 years), of whom 22% had M0, 54% had M1b, and 24% had M1c disease at time of PCa diagnosis. Based on Approaches 1 and 2, the proportion with probable RtB was 5% and 8% among M0, 30% and 30% among M1b, and 25% and 27% among M1c patients. Among M0 patients, the adjusted hazard ratio (AHR) associated with an SRE was 1.27 when using Approach 1 (95% confidence interval, CI: 0.95-1.7) and 1.49 when using Approach 2 (95% CI: 1.14-1.96). However, the impact of SREs on mortality did not differ between both approaches among M1b and M1c patients.

CONCLUSION

We found that alternative measures used to define RtB as SRE in claims data impact conclusions regarding the effect of SREs on mortality among M0 but not M1 patients.

Adjuvant radiotherapy and chemoradiation with gemcitabine after R1 resection in patients with pancreatic adenocarcinoma

Background

The purpose of the study was to evaluate the effect of radiation therapy and chemoradiation with gemcitabine (GEM) after R1 resection in patients with pancreatic adenocarcinoma (PAC).

Methods

We performed a retrospective analysis of 25 patients who were treated with postoperative radiotherapy (RT) or chemoradiation (CRT) after surgery with microscopically positive resection margins for primary pancreatic cancer (PAC). Median age was 60 years (range 34 to 74 years), and there were 17 male and 8 female patients. Fractionated RT was applied with a median dose of 49.6 Gy (range 36 to 54 Gy). Eight patients received additional intraoperative radiotherapy (IORT) with a median dose of 12 Gy.

Results

Median overall survival (mOS) of all treated patients was 22 months (95% confidence interval (CI) 7.9 to 36.1 months) after date of resection and 21.1 months (95% CI 7.6 to 34.6 months) after start of (C)RT. Median progression-free survival (mPFS) was 13.0 months (95% CI 0.93 to 25 months). Grading (G2 vs. G3, P = 0.005) and gender (female vs. male, P = 0.01) were significantly correlated with OS. There was a significant difference in mPFS between male and female patients (P = 0.008). A total of 11 from 25 patients experienced local tumour progression, and 19 patients were diagnosed with either locoregional or distant failure.

Conclusions

We demonstrated that GEM-based CRT can be applied in analogy to neoadjuvant protocols in the adjuvant setting for PAC patients at high risk for disease recurrence after incomplete resection. Patients undergoing additive CRT have a rather good OS and PFS compared to historical control patient groups.