A Novel Therapy for Mesothelioma Patients
Management of mesothelioma has been among the most challenging of cancer
therapy. Most decisive factor in survival remains stage at
diagnosis and type of mesothelioma, with epitheloid type having better survival
compared to sarcomatous type.
Chemotherapy has shown little success in increasing survival.
Although not curative, best results to improve survival comes from patients surviving
pleurectomy (decortication) or
extrapleural pneumonectomy, in combination with chemotherapy and radiotherapy. Both the surgical
procedures are associated with morbidity and mortality and require expertise
such that only few surgeons have the stamina or dare take on these operations.
Almost all patients who undergo surgery have recurrence at some point
in their disease course.
Cryoablation is an alternative minimally invasive procedure used in adjunct
with standard therapies described. Cryoablation uses principles of cold
temperature dissipation to induce thermal injury in target tissues. The
applicators allow conduction of compressed argon gas in applicators interior
hollow chambers (large needle approximately 2 mm in diameter) which in
turn lead to subzero temperatures in the applicator and surrounding tissue
, forming an ice ball (cryo zone) which will kill any cells it engulfs.
Currently the maximum size of iceball attained remains at 4 cm, which
limits ablating large tumors. Although multiple applicators can be used
to reach larger ice balls (with the maximum ice ball obtained by my team
being 9 cm), it does come with increased risk of morbidity .
Currently there are a handful of centers with enough expertise to use cryoablation
in management of mesothelioma. The principal indications to improve survival
include ablation of localized invasive tumor to make the patient eligible
for surgery and ablation of tumor following recurrence. As mentioned previously
almost all patients have localized recurrences and are ineligible for
repeat surgery. Cryoablation can be performed on multiple lesions at a time.
Infrequently, I have ablated up to four lesions in a single ablation setting.
Another set of indications for cryoablation is palliative control of pain.
These tumors invade the chest wall and the ribs and can cause neurogenic
and osseous pain. Even though the survival may not increase, most of my
patients have had improved quality of life after cryoablation. I have
found cryoablation a safe and relatively quick method to control pain.
Finally, cryoablation has been used for focal control of tumor invading
into vital organs like heart to improve quality of life or even survival.
Like all procedures there are some risks involved particularly hemorrhage
and damage to vital structures, which needs to be considered while selecting patients.
Mesothelioma management requires multidisciplinary, strong and individualized
approach to control the tumor early in the course to improve survival
or quality of life.