Dear Hector,

"Capsule" is not at all the right term.

What you mean as "capsule" is connective tissues surrounding the tumor in very early clinical stages of any type of epithelial cancers (carcinomas), which represent about 80% of all cancer types.

Unfortunately, cancer cells rapidly "effract" this "capsule" and invade neigboring tissues and/or metastasize at distance.

Some articles are here attached and relate to the "real cancer life".

Best regards

Robert

There is no such a thing as a real capsule around malignant cells. As Robert says this psedocapsule is mainly made up of conective tissue and other parenchymal cells that have been "pushed" by the tumor cells during its growth. This pseudocapsule lacks basal membrane and it is quickly infiltrated by tumor migration and invasion.

Thanks, this has been really helpful. Then that tissue really is a barrier that tumor cells will eventually penetrate.

Yes Hector.

To make very simple a much more complex story, as long as tumor cells have not invaded this "capsule", the tumor is benign.

In contrast, once tumor cells cross this "barrier", the tumor is considered malignant.

Best regards

Robert

You have to study the expression of extracellular matrix degrading enzymes to understand evaluate the invasive potential of a neoplasm (this is similar to what you have referred to as permeability of the capsule). You can do immunohistochemical analysis on histological sections of the tumor specimen using markers of MMPs, etc.

I disagree Vinay ...

You can invasive cancer processes without any modifications in MMPs, but through modifications of cell volumes and shapes through the activation of ion channels / transporters, etc...

I encourage you to read the publications of Harald Sontheimer in this subject.

No single anti-MMP has been marketed while the concept began 5 decades ago ...

Robert

What methodology would you use to determine invasiveness through those parameters?

As far as I know MMPs can be really useful to determine invasiveness if you know beforehand about a specific MMP that has been expressed in the majority of the tumor but this can change with time and it is possible that it doesn't reflect the entirety of the tumor cell  population´s capacity.

In vitro, you must refer to a single cell biological process, i.e. cell migration, MMPs, transwell migration, etc...

However, if you get "positive" data from any of these in vitro experiments, you cannot conclude about any "antimetastic" effects because metastatic effects MUST be studied i vivo.

Robert

@ Robert Sir. I Agree with you.. we cannot rely on any single anti-MMP. Neoplasm shows multi-faceted behaviour and can never be study by evaluating any one parameter.

Since Hector was mentioning about the permeability of the capsule.. i felt he was talking about capsular invasion in a malignant process. I guess that is what he is intending to study. So the suggestion was to evaluate the process involved in degradation of the collagenous capsule.  Now it all depends on what kind of neoplasm he is intending to study,,

My intent is to study a procedure that requires the injection of a gel in the tumor or its surrounding tissues. Therefore I´m very interested in how much protection does this "capsule" actually gives to the patient (even if it is temporary) and what risks come from the rupture of this barrier. As far as I can tell from your answers, the capsule really is not that protective. Is only a containment that the first invasive cells can easily cross. I´ve read that there is a risk when this tissue gets damaged accidentally since it exposes the tumor cells and increases the probability of local or distant invasion, that makes a lot of sense to me, but I´m wondering if the entry point of a needle can be sealed or fixed in order to avoid this exposure and extra risks for the patient. Currently, my research is focused on colorectal and breast tumors. 

Dear Hector,

This "capsule" is first of all a "spirit view" from human researchers to try to model this complex neoplastic events.

Surgery is by far the most effective treatment to remove a cancer with its capsule and any type of gel will never compete with surgery ...

If the cancer has not yet effract the "capsule", surgeon cures the patient ... and it is the end of the story.

If the cancer already effacted the "capsule" by the time of diagnosis, the metastatic journey will begin and all the weapons will be necessary (surgery, radiotherapy, chemotherapy, immunotherapy, PDT, etc. etc.).

Sorry to not be a high supporter of your approach.

Robert

@ Hector. Seems like the idea is to create a cohesive mass of tumor cells for effective surgical removal. Am I right.  From a patholgical point of view, In highly invasive tumors the amount of collagen production is not sufficient to contain the tumor and the matrix degradation is very high.

Will this gel also help in preventing invasion into the local vasculature?

The gel is just a carrier, it would depend in what kind of drug you would be willing to try. And yeah, my idea is to facilitate surgery by reducing the tumor size. It could also be interesting to apply it near the area of resection while carrying an anti neoplastic agent, it could help to decrease the chance of local recurrence.

Gud luck with the project!!

Dear Hector,

My own experience in this type of domain is to have several surgeons directly involved in your project!

Good luck as already wished by Vinay!

Robert

Right now I am only looking to gather as much information as I can, my intention is to look for the help of several surgeons. As far as I know in my country this gels is not used in surgery and I would like to propose an initial study with animals.

The tissue surrounding slow-growing tumors (mostly seen with benign tumors) is not a capsule, but condensed fibrous tissue, mostly collagen, and is a reaction to the expanding mass (similar to scar tissue). The term 'capsule' is used for the connective tissue at surfaces of organs (kidney, liver, etc.), which develops together with the organ. Some low-grade malignant tumors may also produce this type of fibrous tissue condensation. Assuming I understand the question, permeability, i.e. the ability of molecules to pass through the condensed tissue in either direction, may be difficult to assess, given that the thickness of this tissue can vary a lot, the presence of inflammation varies, and the tumor site may also matter.