Tumors of the Peritoneum

• • The diagnostic work-up typically begins with a specialist clinical evaluation followed by non-invasive imaging studies, which are essential for detecting the presence of ascites or abdominal masses:Abdominal ultrasound

• • CT scan of abdomen and pelvis with contrast medium

• • Magnetic resonance imaging (MRI)

• • PET/TC

When radiological examinations suggest the presence of peritoneal disease, it is necessary to obtain histological confirmation, that is, a microscopic diagnosis of the tumor cells.
This is done through:

• • diagnostic paracentesis

• • percutaneous or laparoscopic biopsy

In many cases, diagnostic laparoscopy is a key step.
This is a minimally invasive procedure that allows direct observation of the peritoneal cavity, evaluation of the extent of disease, and taking samples for histologic examination. This examination also helps determine the resectability of the tumor, that is, whether the disease can be treated surgically.

Over the past 20 years, the treatment of peritoneal carcinosis has made important advances through the development of innovative surgical techniques and therapies. Today, this condition-once considered a terminal phase of the disease-can be addressed in a targeted manner and, in some cases, with curative intent.

The most effective and internationally recognized approach is the combined approach, which combines:

• cytoreductive surgery, aimed at complete or nearly complete removal of visible disease;

• intraperitoneal chemohyperthermia (HIPEC), a procedure that allows direct treatment of the abdominal cavity with heated chemotherapy drugs.

Cytoreductive surgery

The goal of surgery is to remove all macroscopic tumor implants from the peritoneum.
Because chemotherapy drugs penetrate only a few millimeters into the tissue, physical removal of the tumor is a critical step.

The intervention may include:

• The removal of the primary tumor and nearby lymph nodes;

• removal of organs involved in the disease, such as spleen, gallbladder, portions of the stomach or intestines, uterus and adnexa, depending on the spread.

When the disease affects the inner lining of the abdomen, peritonectomy, or partial or total removal of the peritoneum (pelvic, lateral, central, or diaphragmatic), is performed according to now standardized and internationally recognized techniques.
This surgery is performed only when a surgical field free of visible disease can be obtained.

Intraperitoneal chemoperthermia (HIPEC)

After the surgical phase is finished, HIPEC is performed in the same operating session.
During this procedure, the abdominal cavity is “washed” for about 60-90 minutes with a solution of chemotherapy drugs heated to 41-42°C.

Heat enhances the effectiveness of drugs and acts directly on residual cancer cells, damaging their internal structures and reducing the likelihood of recurrence.
Intraperitoneal administration also allows for very high drug concentrations (up to 1000 times higher than in blood) without increasing systemic toxicity.

HIPEC is particularly indicated for tumors that tend to remain confined to the abdominal cavity, such as ovarian, appendicular, and peritoneal tumors.

Pseudomyxoma Peritonei (PMP) is a rare form of mucinous neoplasm that originates in most cases from theappendix and, more rarely, from other organs such as the ovary, colon, or small intestine. It is characterized by the production and accumulation of mucin (mucus) within the abdominal cavity, which can result in a progressive increase in the volume of the abdomen and, in advanced cases, alterations in the function of internal organs.

In the past, the treatment of PMP relied on repeated debulking surgeries (i.e., partial removal of mucinous material and tumor masses), which unfortunately offered limited results: recurrences were very frequent and long-term survival was low, with 5-year survival rates around 6% and perioperative mortality of about 2.7%.

Thanks to advances in research and surgical techniques, today the combination of cytoreductive surgery and intraperitoneal chemohyperthermia (HIPEC) is the gold standard of treatment for this condition.
This approach, introduced and developed by U.S. surgeon Paul Sugarbaker, yields significantly better results: in specialized centers, 10-year survival rates can be as high as80 percent in selected cases.

Treatment of PMP requires a high degree of multidisciplinary expertise and must be performed in referral centers with the necessary skills and technologies to ensure maximum effectiveness and patient safety.

Diffuse malignant peritoneal mesothelioma (DMPM) is a rare form of cancer that originates from the cells of the mesothelium, the thin lining that internally borders the abdominal cavity (peritoneum).
It is a disease mainly related to exposure to asbestos (asbestos) and, in recent years, its incidence has been steadily increasing, parallel to pleural mesothelioma.

DMPM is generally an unresponsive neoplasm to traditional systemic chemotherapy. However, in some cases, this type of treatment can help reduce the volume of disease, making the patient later a candidate for more radical surgery.

As early as 2006, the Consensus Conference of the Peritoneal Surface Oncology Group International (PSOGI) indicated the combination of cytoreductive surgery (CRS) and intraperitoneal chemoperthermia (HIPEC), possibly combined with systemic chemotherapy, as the standard of care for peritoneal mesothelioma.

The clinical progress achieved with this approach is significant: while the median survival with systemic chemotherapy alone was about 12 months, with combined CRS + HIPEC + systemic chemotherapy treatment, the results have more than quadrupled, reaching median survivals of more than 50 months in specialized centers.

Peritoneal carcinosis of colorectal origin is a condition that can arise as an evolution of colon or rectal cancer, when cancer cells spread within the peritoneal cavity.

Thanks to new systemic treatment regimens and the possibility of combination treatments, the median survival of patients with this form is now significantly improved, reaching about 24 months. These data confirm that peritoneal spread represents a biologically distinct entity compared with other forms of colorectal cancer metastasis.

In carefully selected patients, the combination of cytoreductive surgery (CRS) and intraperitoneal chemohyperthermia (HIPEC) yielded even more encouraging results: a median survival of nearly 30 months and a disease-free interval of more than one year.

In light of this evidence, the Italian Association of Medical Oncology (AIOM) has included, already in the 2016 guidelines, the possibility of employing the combined CRS + HIPEC approach in patients with isolated peritoneal carcinosis, provided they are treated in specialized high-volume centers, with teams experienced in the management of this complex pathology.

Epithelial ovarian carcinoma represents the most frequent and aggressive form among gynecologic malignancies. It is often referred to as a “silent tumor,” as in many cases it manifests with few initial symptoms and is diagnosed at an advanced stage (III or IV), when the disease has already spread to the peritoneum.

The standard treatment of advanced ovarian cancer is based on two basic pillars:

• cytoreductive surgery, which aims to remove as much visible disease as possible;

• systemic chemotherapy, to act on residual cancer cells.

The tendency of ovarian carcinoma to spread primarily in the peritoneal cavity has made this disease an ideal model for the use of locoregional treatments that can act directly on the site of disease.

In this context, the combination of cytoreductive surgery (CRS) and intraperitoneal chemohyperthermia (HIPEC) has shown promising results. Initially used mainly in cases of relapse, this strategy is now considered effective even at the time of initial diagnosis, as shown in recent international studies (Van Driel et al., N Engl J Med, 2018).

The combined approach allows, in selected patients treated in highly specialized centers, to significantly improve both overall survival and quality of life, offering new therapeutic perspectives even in the most advanced stages of the disease.

The cancer patient is often a fragile patient, who needs help and support in his or her disease journey: when he or she experiences an ailment, whether related to the disease or a side effect of therapy, he or she should be able to receive a specialist’s opinion quickly, through a “fast track.”

For this reason, at the Candiolo Institute there is an assistance service every day, Monday through Friday from 8 a.m. to 5 p.m.: just call the secretary of the Oncology Day Hospital (011.993.3775 ) reporting the need for an urgent consultation, and the patient is quickly contacted by his or her specialist doctor.

At the Candiolo Institute, specialists from different disciplines are available at Candiolo for patients who need or request them to offer:

• • nutritional support

• • psychological support

• • physiotherapy

• • dressing of venous access devices

• • pain therapy

• • Management of other coexisting conditions.

Social work

The Social Service Department of the Candiolo Institute conducts information and orientation interviews for patients and their families on how to access services in the area and how to obtain welfare and social security benefits provided by law (disability, benefits for aids and prostheses, work leave, etc.).

The service operates on Wednesdays and Fridays from 9 a.m. to 1 p.m. – Phone: 011.993.30

With the conclusion of the course of treatment, the follow-up period begins during which, through a series of examinations and visits, the side effects of the therapies performed, their effectiveness, and the patient’s functional recovery are monitored.

Follow-up examinations are especially important to intercept any recurrences early so that appropriate therapy can be intervened. For the patient, they are also a valuable opportunity for dialogue with their medical specialist.

It is the same specialist physician who schedules follow-up visits, in which the patient’s health condition is assessed and the required test reports are viewed.

Checkups are performed at scheduled intervals for the duration of 5-10 years and include examination, blood chemistry tests, CEA marker assay, Ca19.9, and CT chest and abdomen with contrast medium.

They have a shorter cadence at first (three to six months), then gradually thin out over time (once a year). The frequency and type of examinations provided depend on the stage of the tumor and the treatments given.

Due to the high number of cases treated each year, the Candiolo Institute is a national reference for taking pancreatic cancers. Our experience enables us to deal with even the most complex situations, always with a personalized approach built on the clinical and personal profile of each patient.

Establishing the treatment plan always starts with an accurate and timely diagnosis. Patients have access to state-of-the-art imaging technologies that allow accurate assessment of the extent of the disease.

In addition, the Institute offers advanced and sophisticated laboratory investigations, including molecular and genomic analyses, which are critical for identifying biological features of cancer and guiding therapeutic decisions

When indicated, surgery is performed with minimally invasive techniques (laparoscopic or thoracoscopic), which reduce operative trauma, promote faster recovery, and improve postoperative quality of life. Every treatment choice is defined within the GIC, ensuring a consistent and integrated approach.

As an IRCCS, the Candiolo Institute combines clinical practice with a strong vocation for scientific research. Patients can be evaluated forinclusion in active clinical trials, which represent a real chance to access innovative therapies not yet available in standard practice. Collaboration between care and research is a distinctive value that translates into concrete opportunities for the patient.

The Interdisciplinary Care Group takes care of the person at every stage: from diagnosis to treatment to follow-up, with attention to nutritional support, psychological health, and reintegration into daily life. The organization of checkups, visits and treatment is designed to ensure continuity and serenity, always valuing the human dimension of care.