Pancreas cancer can encase the nearby key arteries. The three arteries that can be involved are hepatic artery (The one that takes blood to the liver), the celiac axis (The artery to the stomach and nearby organs) and the superior mesenteric artery (the artery to the small intestine).
Till recently, the approximation of the tumour mass to any of these vessels was considered incurable and not suitable for surgery. These patients were provided palliative chemotherapy and radiation therapy along with pain control measures. These lesions were considered too advanced.
NCCN guidelines call these lesions as locally advanced pancreatic cancer.
The diagnosis of locally advanced pancreatic cancer is no longer made on the surgical table. With standardised imaging (1) being available in most places, pancreatic surgeons make this diagnosis after imaging evaluation. The obvious next step in evaluation is to look for disease in other major organs like liver, lungs and bone.
A diagnosis of LAPC (locally advanced pancreatic cancer) requires the tumour to be approximated to the 3 arteries mentioned above, with no evidence of distant organ spread (technically called metastases).
This work has been a great burden to pancreatic surgeons all over the world and till recently, we did not have a solution for these patients. We provided palliation in the form of surgery or endoscopic stenting, pain support and all support during the short life. As a young surgeon in 2000, I used to spend a lot of time caring for these patients during the painful part of their life.
To understand this, one must look into the survival of pancreatic cancer patients, when the tumour has involved the arteries. LAPC has a median survival of 16 months while on standard of care chemotherapy(2) All treatments that we intend to provide patients must achieve a better survival compared to this survival.
One of my favourite pancreas specialists, who work I eagerly follow is Dr. Kathleen Christians, from the University of Wisconsin. Her team classifies LAPC into 2 types: Type A and Type B, based on the extent of circumferential involvement of the arteries in the near vicinity of the cancer tissue. (3) Type A lesions can be treated with chemotherapy before surgery and then 80% of the patients can have the tumour completely removed. Patients whose cancer could be removed by surgery had a median survival of around 35 months, which is double the survival.
All these patients undergo chemotherapy prior to surgery - technically known as Induction chemotherapy or neoadjuvant chemotherapy. The European Journal of Surgical Oncology in 2018 (4) published a study enquiring the role of induction chemotherapy in both locally advanced and borderline resectable pancreatic cancer. In every key aspect of pancreatic surgery, the induction chemotherapy group fared better - post operative complication, pancreatic fistula rate, peripancreatic fat invasion, lymph node spread control and in surgical clearance - much better than upfront surgery. This also has been our experience too. And we actively encourage patients to take up induction chemotherapy especially in locally advanced pancreatic cancer.
As early as 2016, the Heidelberg group published their work on induction chemotherapy in pancreatic cancer
If we know that induction chemotherapy works, how do we choose between the regimens? A recent European multi center trial named NEOLAP explored this question. Our options in pre surgical chemotherapy (Technically known as neoadjuvant chemotherapy) are FOLFIRINOX ( a combination of 5FU, irinotecan, oxaliplatin and leucovorin) and GEM - Ambraxane (Gemcitabine + nab- paclitaxel)
NEOLAP showed better conversion rate - more chance of having the tumour removed by surgery - after sequential FOLFIRINOX, the regimen with which we have the best experience too.
Source file: https://www.esmo.org/oncology-news/Secondary-Resectability-Improved-with-Induction-Chemotherapy-in-Locally-Advanced-Pancreatic-Cancer. There is a slight advantage for the sequential FOLFIRINOX regimen in the conversion rate - leading to better survival as the resected patients definitely fared better.
So to conclude, pancreatic cancers that have involved the arteries do not mean your hope is lost. We are getting better at providing these patients with longer survival and the best news is that we are doing this in Chennai on a regular basis. So keep your chin up and step up for a fight. For we can do this together.
References:
(1) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6284179/#:~:text=The%20most%20important%20types%20of,resonance%2C%20and%20positron%20emission%20tomography.
(2) https://pubmed.ncbi.nlm.nih.gov/29596120/
(3) 10.1016/j.surg.2017.09.012
(4) 10.1016/j.ejso.2018.07.057
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