In gastrointestinal cancers, radiological examinations such as tomography or MRI may reveal invasion (adhesion/attachment) of cancer to surrounding tissues or organs. In some patients, a similar situation may be noticed during surgery. Examples of this include colon cancer involving the small intestine, stomach cancer involving the spleen, rectal cancer involving the prostate or uterus, and pancreatic cancer involving the portal veins.
If the radiological examinations show that the cancer has adhered to surrounding organs, the treatment decision depends on the organ of origin and the tissue/organ involved. In some tumors, treatment may begin with chemotherapy and/or radiotherapy, followed by surgery after a certain period, while in others, the tumors are directly removed through surgery.
Before surgery, the surgeon must make a thorough radiological assessment to determine which organs will be removed along with the organ of origin. Additionally, during radiological examinations, the possibility of detecting adhesions during surgery should be considered, and both the patient and their relatives should be prepared for the possibility of additional organ removal.
At this point, one might wonder, “Isn’t it sufficient to remove the organ of origin of the cancer?”
As expected, the adhesion of cancer to surrounding organs may indicate that cancer cells have started to penetrate the adjacent organ. Leaving the organ adhered to by cancer in place while only removing the organ of origin may lead to the spread of cancer cells into the abdominal cavity and the progression of the disease.
Another question that may arise is, “Does the adhesion of cancerous tissue to surrounding organs necessarily occur due to the progression of cancer?”
We can approach this question in two ways. If it is clearly visible on tomography or MRI that cancer has entered the surrounding organ, there is no doubt in such cases. In this group, in patients who have the chance of being operated on, cancer cells in the removed surrounding organ can be seen in pathological examination.
On the other hand, in patients where there is suspicion of adhesion radiologically, or where it is clearly visible during surgery that cancer has not penetrated, the situation may be different. It is known that cancer cells can adhere to surrounding organs through an inflammatory reaction called desmoplastic reaction. This situation is particularly observed at a higher rate if an infection has developed within the tumor or in the remaining part of the organ connected to the tumor. If desmoplastic reaction is present in the patient, removing the surrounding organ may be unnecessary and may increase the risk of surgery. On the other hand, if there is adhesion due to the tumor but it is evaluated as desmoplastic reaction and the adhered organ is left in place, the tumor will remain in the abdominal cavity. It is often not possible to make this distinction.
In scientific studies on colorectal cancer, where it is assumed that every adhesion is due to cancer, and additional organs are removed and it is checked pathologically whether there is a tumor, it has been observed that adhesion due to the tumor occurs in up to 30% of cases. In other words, in cases where there is no obvious invasion, the removal of the adhered organ is unnecessary in 70% of cases. At this point, instead of focusing on the idea that removing the adhered organ will be unnecessary in 70% of cases, it is recommended to focus on the idea that if the organ is not removed, cancer cannot be completely removed in 30% of cases. That is, it is recommended to remove the adhered organ if there is doubt during surgery.
The organ to which the cancerous tissue is adhered must be removed as a whole (en bloc). For example, in a colon tumor adhered to the uterus, the colon and uterus must be removed together without separation to prevent tumor spread. Even if the surgeon first separates the colon and then completely removes the uterus and ovaries, the risk of recurrence will be very high because cancer cells will have spread.
It has been mentioned earlier that in tumors adhered to surrounding organs, oncological treatments or direct surgery can be initiated. At this stage, treatment approaches for cancers grown according to organs can be found below with examples.
In cases of gastric cancer, if the tumor has invaded the gastric wall and adhered to surrounding tissues, chemotherapy is initiated first regardless of which tissue it adhered to. After a certain period of chemotherapy, radiological evaluations are performed to check if the tumor has shrunk. If the desired degree of shrinkage has occurred and the adhered organ can be removed along with the tumor, the patient undergoes surgery.
If necessary, the spleen, tail or body of the pancreas can be removed in gastric cancer cases. In some patients, removal of the colon, diaphragm muscle, abdominal wall, liver tissue may also be required.
Similarly to gastric cancer, chemotherapy is initiated in cases of pancreatic cancer with cancer presence towards surrounding tissues. However, due to anatomical features, some patients with pancreatic cancer may be considered initially inoperable. In cases considered operable on the border, if sufficient shrinkage is seen after chemotherapy ± radiotherapy, surgery can be performed. In pancreatic cancer, cases may arise where the stomach, colon, or portal vein need to be removed.
In cases of colon cancer with adhesion to surrounding organs, surgery is often the first treatment option. Since the colon is in contact with a large area in the abdomen, it can invade many organs. Therefore, during interventions to eliminate colon cancer, organs such as the stomach, duodenum, small intestines, pancreas, gallbladder, liver, uterus, ovaries, bladder, and spleen may need to be removed. Although preoperative chemotherapy application for advanced colon cancers has been considered lately, it has not been widely accepted. As ongoing studies progress, the practice of starting with chemotherapy similar to stomach or pancreatic cancer may be highlighted. On the other hand, there are also studies recommending the evaluation of these patients with genetic analyses and starting immunotherapy if appropriate.
In cases of rectal cancer, when adhesion to surrounding organs is observed, it is a accepted approach to reduce the tumor by giving radiotherapy and, in some cases, chemotherapy. After treatments extended up to 6 months depending on the condition, the surgical approach is decided after radiological evaluation. Depending on the progression of rectal cancer in surrounding tissues, it is recommended to remove either the wall or the entirety of the organ to which it adhered. In rectal cancer, structures such as the prostate, seminal vesicles, bladder, coccyx or sacrum bone, vagina, uterus, and ovaries may need to be removed.
Depending on factors such as the patient’s body structure, the size of the tumor, and the surgeon’s experience, multi-organ removal surgeries can be performed openly, laparoscopically, or robotically.
In surgeries where multiple organs are removed, the duration of the operation is longer, there is more blood loss, and the need for intensive care is higher. The probability of complications during and after surgery may also be higher. Accordingly, the hospitalization period may be prolonged.
Despite all these negative situations, for effective oncological surgery, all tissues and organs in contact with cancer must be removed with clean surgical margins in patients where it is deemed necessary.
