Tumour cryoablation combined with palliative bypass surgery in the treatment of unresectable pancreatic cancer

Although cryosurgery has been proved to be an effective treatment to extend the survival time of unresectable liver cancer patients and improve their quality of life, few surgeons actually treat unresectable pancreatic cancer with this method because of its safety risks. This study aims to evaluate the safety and efficacy of cryosurgical ablation in the treatment for unresectable pancreatic cancer.

Methods A retrospective study was conducted on 142 patients who underwent palliative bypass with cryoablation (PBC group: 68) or without cryoablation (PB group: 74) for unresectable pancreatic cancer from 1995 to 2002. The morbidity and 5 year survival rates of the two groups were compared. Carbohydrate antigen 19–9 (CA19-9) level and tumour size were evaluated in PBC group.

Results There was no significant difference in the rate of overall complications between the two groups (p=0.809), except for a higher delayed gastric emptying rate observed in the PBC group (36.8% vs 16.2%, p=0.005). In the PBC group, the median preoperative CA19-9 concentration decreased from 690 U/ml to 56 U/ml (p=0.000). CT scan results of 55 patients indicated that tumour mass shrinkage occurred in 36 of them, from 4.3 cm to 2.4 cm (pre-ablation to 3 months after ablation). Kaplan–Meier analysis showed no significant difference in 5 year survival rates between the two groups (p=0.124).

Conclusions Cryosurgery combined with palliative bypass surgery can be considered a safe and effective treatment for unresectable pancreatic cancer. Though this technique remains only palliative, it may be further employed to improve advanced stage pancreatic cancer.


Distant metastasis occurs late during the genetic evolution of pancreatic cancer

Metastasis, the dissemination and growth of neoplastic cells in an organ distinct from that in which they originated1, 2, is the most common cause of death in cancer patients. This is particularly true for pancreatic cancers, where most patients are diagnosed with metastatic disease and few show a sustained response to chemotherapy or radiation therapy3. Whether the dismal prognosis of patients with pancreatic cancer compared to patients with other types of cancer is a result of late diagnosis or early dissemination of disease to distant organs is not known. Here we rely on data generated by sequencing the genomes of seven pancreatic cancer metastases to evaluate the clonal relationships among primary and metastatic cancers. We find that clonal populations that give rise to distant metastases are represented within the primary carcinoma, but these clones are genetically evolved from the original parental, non-metastatic clone. Thus, genetic heterogeneity of metastases reflects that within the primary carcinoma. A quantitative analysis of the timing of the genetic evolution of pancreatic cancer was performed, indicating at least a decade between the occurrence of the initiating mutation and the birth of the parental, non-metastatic founder cell. At least five more years are required for the acquisition of metastatic ability and patients die an average of two years thereafter. These data provide novel insights into the genetic features underlying pancreatic cancer progression and define a broad time window of opportunity for early detection to prevent deaths from metastatic disease.

source: nature