Prognostic analysis of patients with pancreatic head adenocarcinoma less than 2 cm undergoing resection

A retrospective preliminary study of intrapancreatic late enhancement as a noteworthy imaging finding in the early stages of pancreatic adenocarcinoma

OBJECTIVE

To characterize intrapancreatic late enhancement (ILE) observed in the early stages of pancreatic adenocarcinoma (PAC).

METHODS

Among 203 patients pathologically diagnosed with PAC between October 2011 and February 2021, 32 patients with pre-diagnostic abdominal contrast-enhanced CT performed from 6 months to 5 years before the diagnosis were enrolled in this study. Indirect findings (IFs) on pre-diagnostic CT, including ILE, were evaluated and examined for various clinical data and time intervals to diagnosis (TIDs). The detected ILE was quantitatively evaluated, and the effect of ILE awareness on lesion detection by two radiologists and their interobserver agreement were assessed.

RESULTS

Among the 32 patients, 23 showed IFs. ILE was observed in 14 patients (63%), with a median TID of 17 months (interquartile ratio [IQR]: 9.3-42.3). ILE alone was observed in eight patients (35%), ILE with focal pancreatic parenchymal atrophy (FPPA) was observed in five patients (22%), and ILE with main pancreatic duct abnormalities (MPDA) was observed in one patient (4%). Pancreatic head lesions were significantly more frequent in patients with ILE alone than in patients with FPPA or MPDA (p = 0.026). The median long-axis diameters of the region with ILE and ILE-to-pancreas contrast were 10 (IQR: 5-11) mm and 24 (IQR: 17-33) HU, respectively. Awareness of ILE led observers to detect two or three more pancreatic head lesions, and interobserver agreement increased from poor agreement (k = 0.17) to moderate agreement (k = 0.55).

CONCLUSION

ILE is a significant IF for early PAC detection.

KEY POINTS

• Intrapancreatic late enhancement (ILE) is a significant indirect finding in the early detection of pancreatic adenocarcinoma. • ILE without other indirect findings is expected to help detect pancreatic head lesions. • Image evaluation focusing on ILE can increase lesion detection and improve the interobserver agreement.

Management of Pancreatic Cancer and Its Microenvironment: Potential Impact of Nano-Targeting

Simple Summary

The poor prognosis and survival rates associated with pancreatic cancer show that there is a clear unmet need for better disease management. The heterogeneity of the tumor and its microenvironment, including stroma and fibrosis, creates a challenge for current therapy. The pathogenesis of pancreatic cancer is mediated by several factors, such as severed communication between pancreatic stellate cells and stroma and the consequences of hypoxia-inducible factors that aid in the survival of the pancreatic tumor. Given the multiple limitations of molecular targeting, multiple functional nano-targeting offers a breakthrough in pancreatic cancer treatment through its ability to overcome the physical challenges posed by the tumor microenvironment, amongst many others.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is rare and difficult to treat, making it a complicated diagnosis for every patient. These patients have a low survival rate along with a poor quality of life under current pancreatic cancer therapies that adversely affect healthy cells due to the lack of precise drug targeting. Additionally, chemoresistance and radioresistance are other key challenges in PDAC, which might be due in part to the lack of tumor-targeted delivery of sufficient levels of different chemotherapies because of their low therapeutic index. Thus, instead of leaving a trail of off-target damage when killing these cancer cells, it is best to find a way that targets them directly. More seriously, metastatic relapse often occurs after surgery, and therefore, achieving improved outcomes in the management of PDAC in the absence of strategies preventing metastasis is likely to be impossible. Nano-targeting of the tumor and its microenvironment has shown promise for treating various cancers, which might be a promising approach for PDAC. This review updates the advancements in treatment modalities for pancreatic cancer and highlights future directions that warrant further investigation to increase pancreatic patients’ overall survival.

Impact of tumor size on survival of patients with resected pancreatic ductal adenocarcinoma: a systematic review and meta-analysis

Background

The impact of tumor size on prognosis for surgically treated patients with pancreatic ductal adenocarcinoma (PDAC) remains controversial. A systematic review and meta-analysis was performed to evaluate this issue.

Methods

Relevant studies published from January 2000 to June 2017 were identified through EMBASE and PUBMED. Data were pooled for meta-analysis using Review Manager 5.3.

Results

Twenty eight observational studies involving a total of 23,945 patients were included. Tumors > 2 cm was associated with poor prognosis: the pooled hazard ratio (HR) estimate for overall survival was 1.52 (95% confidence interval [CI]: 1.41–1.64; P < 0.0001) by univariate analysis and 1.61 (95% CI: 1.35–1.91; P < 0.0001) by multivariate analysis; the pooled HR estimate for disease-free survival was 1.74 (95% CI: 1.46–2.07; P < 0.0001) by univariate analysis and 1.38 (95% CI: 1.12–1.68; P = 0.002) by multivariate analysis. When compared with patients with tumors ≤2 cm, those with the tumors > 2 cm had higher incidences of lymph node metastasis, poor tumor differentiation, lymph vessel invasion, vascular invasion, perineural invasion, and positive intraoperative peritoneal cytology.

Conclusion

These data demonstrate that PDAC size > 2 cm is an independent predictive factor for poor prognosis after surgical resection and associated with more aggressive tumor biology.

CT Imaging Biomarkers Predict Clinical Outcomes After Pancreatic Cancer Surgery

This study aimed to determine whether changes in contrast-enhanced computed tomography (CT) parameters could predict postsurgery overall and progression-free survival (PFS) in pancreatic cancer patients. Seventy-nine patients with a final pathological diagnosis of pancreatic adenocarcinoma were included in this study from June 2008 to August 2012. Dynamic contrast-enhanced (DCE) CT of tumors was obtained before curative-intent surgery. Absolute enhancement change (AEC) and relative enhancement change (REC) were evaluated on DCE-CT. PFS and overall survival (OS) were compared based on CT enhancement patterns. The markers of fibrogenic alpha-smooth muscle antigen (α-SMA) and periostin in tumor specimens were evaluated by immunohistochemical staining. The χ test was performed to determine whether CT enhancement patterns were associated with α-SMA-periostin expression levels (recorded as positive or negative). Lower REC (<0.9) was associated with shorter PFS (HR 0.51, 95% CI: 0.31-0.89) and OS (HR 0.44, 95% CI: 0.25-0.78). The α-SMA and periostin expression level were negatively correlated with REC (both P = 0). Among several CT enhancement parameters, REC was the best predictor of patient postsurgery survival. Low REC was associated with a short progression-free time and poor survival. The pathological studies suggested that REC might be a reflection of cancer fibrogenic potential.

Indications for staging laparoscopy in pancreatic cancer

BACKGROUND

To identify indications for staging laparoscopy (SL) in patients with resectable pancreatic cancer, and suggest a pre-operative algorithm for staging these patients.

METHODS

Relevant articles were reviewed from the published literature using the Medline database. The search was performed using the keywords 'pancreatic cancer', 'resectability', 'staging', 'laparoscopy', and 'Whipple's procedure'.

RESULTS

Twenty four studies were identified which fulfilled the inclusion criteria. Of the published data, the most reliable surrogate markers for selecting patients for SL to predict unresectability in patients with CT defined resectable pancreatic cancer were CA 19.9 and tumour size. Although there are studies suggesting a role for tumour location, CEA levels, and clinical findings such as weight loss and jaundice, there is currently not enough evidence for these variables to predict resectability. Based on the current data, patients with a CT suggestive of resectable disease and (1) CA 19.9 ≥150 U/mL; or (2) tumour size >3 cm should be considered for SL.

CONCLUSION

The role of laparoscopy in the staging of pancreatic cancer patients remains controversial. Potential predictors of unresectability to select patients for SL include CA 19.9 levels and tumour size.

The advances of Midkine with peripheral invasion in pancreatic cancer

Pancreatic cancer is a deadly malignancy associated with rapid progression and poor prognosis. Perineural invasion (PNI) in pancreatic cancer is one of the most common characteristics of this disease, with incidence of nerve invasion between 53.3% and 90%. PNI is also associated with disease recurrence and pain. Despite research efforts, the detailed mechanisms underlying PNI in pancreatic cancer remains unknown. The main factors of PNI in pancreatic cancer will be introduced in the following: 1. The anatomy of the pancreas nerve: The cancer cells along the blood vessels, lymphatic vessels, peripheral nerve gap and perineurium to Invasion. 2. Adhesion molecules in PNI: Neural cell adhesion molecules. 3. Growth factor: For example, nerve growth factor and tyrosine kinase receptor A; Neurotrophic factor and its receptor, etc. 4. The others: Such as matrix metalloproteinases, integrin. A neurite growth promoting factor and neuritrophic factor known to have a role in the pathophysiology of pancreatic cancer by inducing neuritis growth is midkine. In this review, we discuss the role of midkine and other growth and neurotrophic factors on the pathophysiology of PNI in pancreatic cancer.

The Association Between Chemoradiation-related Lymphopenia and Clinical Outcomes in Patients With Locally Advanced Pancreatic Adenocarcinoma

OBJECTIVES

Lymphopenia is a common consequence of chemoradiation therapy yet is seldom addressed clinically. This study was conducted to determine if patients with locally advanced pancreatic cancer (LAPC) treated with definitive chemoradiation develop significant lymphopenia and if this affects clinical outcomes.

METHODS

A retrospective analysis of patients with LAPC treated with chemoradiation at a single institution from 1997 to 2011 was performed. Total lymphocyte counts (TLCs) were recorded at baseline and then monthly during and after chemoradiation. The correlation between treatment-induced lymphopenia, established prognostic factors, and overall survival was analyzed using univariate Cox regression analysis. Important factors identified by univariate analysis were selected as covariates to construct a multivariate proportional hazards model for survival.

RESULTS

A total of 101 patients met eligibility criteria. TLCs were normal in 86% before chemoradiation. The mean reduction in TLC per patient was 50.6% (SD, 40.6%) 2 months after starting chemoradiation (P<0.00001), and 46% had TLC<500 cells/mm. Patients with TLC<500 cells/mm 2 months after starting chemoradiation had inferior median survival (8.7 vs. 13.3 mo, P=0.03) and PFS (4.9 vs. 9.0 mo, P=0.15). Multivariate analysis revealed TLC<500 cells/mm to be an independent predictor of inferior survival (HR=2.879, P=0.001) along with baseline serum albumin (HR=3.584, P=0.0002), BUN (HR=1.060, P=0.02), platelet count (HR=1.004, P=0.005), and radiation planning target volume (HR=1.003, P=0.0006).

CONCLUSIONS

Severe treatment-related lymphopenia occurs frequently after chemoradiation for LAPC and is an independent predictor of inferior survival.

Poor prognosis of common-type invasive ductal carcinomas that originate in the branching pancreatic duct

PURPOSE

To clarify the incidence, clinicopathological features and prognosis of pancreatic invasive ductal carcinomas (IDCs) with different tumor origin sites in the pancreatic duct.

METHODS

Based on the relationship between the invasive cancer area (ICA) and the main pancreatic duct (MPD), IDCs less than 2 cm in diameter were classified into two groups: type I, in which the ICA and MPD were separated, and type II, in which the MPD passed through the ICA. The clinicopathological findings and prognosis of each type were compared in a total of 37 patients.

RESULTS

The incidences of IDC types I and II were 18.9 and 81.1 %, respectively. Although there was no difference in local invasion, both node involvement and venous invasion tended to occur more frequently in type I IDC, and the three-year survival rate was significantly lower for type I (28.6 %) than type II (71.8 %) IDC.

CONCLUSIONS

The prognosis of IDCs that originated in the branching pancreatic duct (BPD) distant from the MPD (type I) was worse than the prognosis of IDCs that originated in either the MPD or the BPD close to the MPD (type II). These data suggest that the progression and degree of malignancy of IDCs may vary depending on the site of tumor origin in the pancreatic duct.

Recombinant lentivirus targeting the pleotrophin gene reduces pleotrophin protein expression in pancreatic cancer cells and inhibits neurite outgrowth of dorsal root ganglion neurons

The objectives of the present study were to construct the recombinant primate lentivirus‑short hairpin RNA-pleiotrophin (pLV-shRNA-PTN) vector, to investigate the silencing effect of pLV-shRNA-PTN on PTN expression in MIA PaCa-2 cells and to observe the inhibition efficiency of pLV-shRNA‑PTN on neurite outgrowth from dorsal root ganglion (DRG) neurons in vitro. The construction procedure for recombinant lentivirus pLV-shRNA-PTN has been described previously. In the present study, pLV-shRNA‑PTN was used to infect MIA PaCa-2 pancreatic cancer cells and the efficiency of the knockdown of the PTN gene on day 7 following infection was analyzed using western blotting. The morphological changes in the cultured DRG neurons were observed by monoculture of DRG neurons and co-culture with MIA PaCa-2 cells in vitro. The recombinant lentivirus pLV-shRNA‑PTN was successfully constructed. The western blot analysis showed that the inhibition rates of PTN expression were 46, 80, 20 and 21%, respectively, following pLV-shRNA‑PTN-A, B, C and D infection. pLV-shRNA-PTN‑B showed the highest knockdown efficiency. DRG neurons co-cultured with infected MIA PaCa-2 cells were decreased in size when compared with the control, and there was a significant decrease in the number and length of neurites. The results suggest that efficient and specific knockdown of PTN in MIA PaCa-2 pancreatic cancer cells and the subsequent reduction in PTN expression results in the inhibition of neurite outgrowth from DRG neurons.

Survival among pancreaticoduodenectomy patients treated for pancreatic head cancer <1 or 2 cm

BACKGROUND

Size of primary tumor has implications for staging, imaging, and treatment of pancreatic head carcinomas. Limited data suggest that small tumor size is associated with better survival. The objective of this population study is to analyze characteristics and survival of patients with resected pancreatic head ductal carcinomas sized <1 and 2 cm.

METHODS

Analysis of resected invasive pancreatic head ductal carcinomas captured within SEER Program from 1998 to 2008.

RESULTS

A total of 7,135 cases were analyzed with nodal metastases in 31, 55, and 67 % for subcentimeter, 1.1-2 cm, and >2 cm tumors, respectively. Median survival was longest for node-negative tumors (38, 26, 19 months for tumors measuring ≤ 1, 1.1-2, and >2 cm, respectively; p < 0.001) versus node-positive tumors (18, 19, 14 months, p < 0.001). In multivariate analysis, large tumor size was associated with higher risk of death (hazard ratio (HR) = 1.179 for tumors 1.1-2 cm, p = 0.152; HR = 1.665 for tumors >2 cm, p < 0.001).

CONCLUSIONS

Small pancreatic cancers have a poor prognosis and surprisingly high rate of nodal involvement; therefore, they cannot be considered early cancers. Size-based screening is unlikely to save lives with current treatment options.

Small (≤ 20 mm) pancreatic adenocarcinomas: analysis of enhancement patterns and secondary signs with multiphasic multidetector CT

PURPOSE

To evaluate the enhancement patterns, prevalence of secondary signs, and histopathologic features of 20-mm-diameter or smaller pancreatic cancers seen on multiphasic multidetector computed tomographic (CT) images.

MATERIALS AND METHODS

This retrospective study was approved by the institutional review board; the requirement for informed consent was waived. From January 2002 through September 2009, the authors reviewed the clinical and imaging data of 130 consecutive patients (76 men, 54 women; mean age, 64.1 years; age range, 28-82 years) who had surgically proven 30-mm-diameter or smaller pancreatic cancers and underwent preoperative multidetector CT and 33 consecutive patients (17 men, 16 women; mean age, 65.1 years; age range, 48-84 years) who had histopathologically proven pancreatic cancer and underwent incidental multidetector CT before the diagnosis was rendered. Only pancreatic phase CT was performed in two patients, and only hepatic venous phase CT was performed in nine patients. Two radiologists in consensus classified the tumor attenuation as hyper-, iso-, or hypoattenuation during the pancreatic and hepatic venous phases. Accompanying secondary signs, temporal changes in tumor attenuation, and histopathologic findings also were analyzed. The Fisher exact test, χ(2) test, generalized estimating equation, and Student t test were used to compare the variables.

RESULTS

Seventy tumors were 20 mm or smaller, and 93 were 21-30 mm. Isoattenuating pancreatic cancers were more commonly observed among the 20-mm or smaller tumors (16 of 59, 27%) than among the 21-30-mm tumors (12 of 93, 13%) (P = .033). They were also more common among well-differentiated tumors (seven of 12, 58%) than among moderately differentiated (20 of 124, 16%) and poorly differentiated (one of 10, 10%) tumors (P = .001). The prevalence of secondary signs differed significantly according to tumor size (53 [76%] of 70 ≤20-mm tumors vs 92 [99%] of 93 21-30-mm tumors) (P < .001). The prevalence of secondary signs was high among isoattenuating pancreatic cancers (14 [88%] of 16 ≤20-mm tumors vs all 12 [100%] 21-30-mm tumors). Most of the isoattenuating tumors seen at prediagnostic CT were hypoattenuating after 6 months (100% [four of four] during pancreatic phase, 71% [five of seven] during hepatic venous phase).

CONCLUSION

The prevalence of isoattenuating pancreatic cancers differed significantly according to tumor size and cellular differentiation. Most small isoattenuating pancreatic cancers showed secondary signs.

SUPPLEMENTAL MATERIAL

http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11101133/-/DC1.