Professor Robert Rosenberg is an expert in visceral and tumor surgery and is head of the Department of General and Visceral Surgery at Baselland Cantonal Hospital. He is also Head of the Abdominal Center and heads the certified Colon Cancer Center there, which is one of the leading facilities in Switzerland. As a senior intestinal surgeon with extensive experience in oncological surgery, he has proven expertise in the treatment of malignant diseases of the gastrointestinal tract.
Prof. Dr. Rosenberg completed his training at the Klinikum rechts der Isar in Munich, but also at renowned clinics in the USA, which underlines his well-founded, international surgical expertise. His treatment spectrum covers the entire field of general and visceral surgery with a particular focus on minimally invasive surgery, tumor surgery, gastric surgery, colon and rectal surgery. He is also an experienced surgeon in the region in robot-assisted surgical techniques using the Da Vinci system.
The indication for surgery and the procedures are based on current scientific standards and national and international guidelines, always individually tailored to the patient's needs. The surgical department in Liestal and at Bruderholz, right next to Basel, offers comprehensive care at the highest medical level with its broad spectrum and a well-coordinated interdisciplinary team.
Prof. Dr. Rosenberg provides further insights into his work and his commitment to intestinal health in another interview with the editors of the Leading Medicine Guide, this time on modern therapy for rectal cancer.
Rectal cancer, a malignant tumor of the rectum, usually develops from benign changes to the mucous membrane such as adenomas or polyps, which can develop into cancer over a period of years. The causes of this degeneration are manifold. In addition to genetic factors, such as a family history or hereditary diseases such as Lynch syndrome or familial adenomatous polyposis, lifestyle factors and the environment also play a significant role.
Professor Dr. Rosenberg explains at the beginning of our conversation: “The term rectal cancer is not very familiar to the general public. Ultimately, however, we are talking about this clinical picture: a malignant tumor of the intestine that affects the last 16 centimetres - measured from the anus inwards. We refer to everything in this section as rectal cancer and treat it as such. The rest of the bowel, i.e. further up, falls under colon carcinoma, which is what is classically understood as bowel cancer. There are many causes of rectal cancer. Much is not yet fully understood, but we do know that our western lifestyle plays a major role. A low-fiber, high-fat diet with lots of red meat has been shown to increase the risk. Lack of exercise, obesity, regular alcohol consumption and smoking are other known risk factors. There are also genetic influences. We assume that around 10 to 15 percent of patients have a genetic predisposition. We know of some specific genetic mutations, but there are also genetic variants whose exact effects are not yet fully understood. Chronic inflammatory bowel diseases such as ulcerative colitis also increase the risk."
Symptoms usually only appear at an advanced stage. This is what makes rectal cancer so insidious. “At the beginning, the disease is usually asymptomatic, which underlines the importance of screening. Colonoscopy is the most important procedure here and is recommended in Switzerland, but also in Germany, in order to detect early stages. When symptoms do occur, they are usually classic warning signs such as blood in the stool, changes in bowel habits - for example alternating between diarrhoea and constipation or pencil-thin stools -, unintentional weight loss, tiredness, abdominal pain or flatulence,” explains Prof. Dr. Rosenberg, explaining how the diagnosis is made and which age groups are most likely to be affected:
“Diagnostics comprises several steps. It usually starts with a colonoscopy. The tumor is localized and made visible, and tissue samples can be taken. Once the tumor has been detected, the next step is to clarify how advanced the disease is. This includes imaging procedures such as computer tomography to assess metastases, for example in the lungs or liver, magnetic resonance imaging or an internal ultrasound to assess the extent of the rectal tumor. Today, molecular genetic diagnostics are also part of the standard clarification, as certain markers can provide information on the optimal therapy. As far as age is concerned, rectal cancer is typically a disease of older people - we see it most frequently from the age of 70. But unfortunately, there is alarming evidence that more and more younger people are also affected, i.e. under the age of 50. This makes it clear that no one is automatically 'too young' for this disease. The causes of this have not been conclusively clarified, but I personally attribute it strongly to changes in eating habits - and to external influences that we often cannot influence directly. Nowadays, many people hardly take the time to eat freshly prepared food and are quick to turn to ready-made products, which are often not very good for their health."
Neoadjuvant therapy plays a central role in the modern treatment of rectal cancer, especially for locally advanced tumors in the middle and lower rectum.
“The treatment strategies for rectal cancer are much more complex than for classic colon cancer. While the latter is usually operated on directly in a non-metastatic situation, the focus in rectal cancer is often initially on neoadjuvant therapy, especially for locally advanced tumors. This means that a combined pre-treatment with radiotherapy and chemotherapy is carried out before a possible operation. This procedure has established itself as the standard, particularly for medium-sized tumors that were no longer detected as early findings through screening but already have a certain local extent. The aim of this neoadjuvant therapy is to shrink the tumor before surgery or, ideally, to make it disappear completely. In around 30 to 40 percent of cases, it is now possible to achieve a complete tumor response using modern treatment protocols - with the result that surgery may no longer be necessary. A major advantage of this approach is the improved local tumor control and the significantly reduced recurrence rate. In addition, successful neoadjuvant treatment can even preserve the rectum in selected cases. For affected patients, this means not only a cure, but also a gain in quality of life,” says Prof. Dr. Rosenberg.
Neoadjuvant therapy has been used for over two decades. It was originally introduced because oncological outcomes for rectal cancer were found to be worse than for colon cancer.
Prof. Dr. Rosenberg comments: “Radiation was therefore initially used to reduce the risk of recurrence. At the same time, the concept of so-called total mesorectal excision (TME) was added - a surgical standard in which the surrounding tissue of the rectum is removed as completely as possible. The combination of precise surgical technique and radiotherapy has significantly improved local control. In recent years, the concept of neoadjuvant therapy has evolved: Today, chemotherapies that used to be administered only after surgery are used before surgery. These intensified protocols not only improve relapse control, but also open up new options such as foregoing surgery in the event of a complete tumor response. This development shows how dynamic and differentiated the modern treatment of rectal cancer has become - with the clear aim of reconciling cure and quality of life."
Today, the decision between local organ-preserving therapy and radical rectal resection for rectal cancer is made on an individualized and interdisciplinary basis - with careful consideration of oncological safety, functional results and the patient's quality of life.
This decision is based primarily on the exact tumor characteristics, the response to neoadjuvant therapy, the general condition and the personal wishes of the patient. Precise preoperative diagnostics are of central importance. "“Organ-preserving” in this context means that no surgery is performed in the classic sense - i.e. no organ, in this case the rectum, is removed. However, there are various situations in which it is possible to speak of organ preservation. In the case of very early tumor findings, so-called early carcinomas, it is actually possible to remove the tumor without extensive surgery. In such cases, the gastroenterologist can remove the tumor during a colonoscopy. This procedure can also be performed surgically, provided the tumor is in a clearly defined early stage. However, as soon as the tumor has reached a more advanced stage, i.e. is in an intermediate stage, the situation becomes more complex. In these cases, there is not only a risk from the primary tumor itself, but also from possible metastases in neighbouring lymph nodes. These potential lymph node metastases make it necessary to remove an entire segment of the rectum in order to ensure oncologically safe treatment. In such cases, it is no longer possible to speak of organ-preserving therapy. Another approach is neoadjuvant therapy, which can cause the tumor to recede completely - in other words, it literally 'melts away'. In such cases, surgery may no longer be necessary. Instead, patients can be closely monitored and checked regularly. Today, this procedure makes it possible to spare many patients the removal of the rectum,” explains Prof. Dr. Rosenberg.
Ultimately, the treatment decision is based on a careful risk-benefit assessment and discussion in the interdisciplinary tumor board, which includes surgeons, oncologists, radiotherapists, gastroenterologists and radiologists. The patient's life situation, functional expectations and individual preferences also play an increasingly important role in the decision.
Robotic-assisted surgery has fundamentally changed the surgical treatment of rectal cancer in recent years and set new standards in precision, protection of sensitive structures and patient experience. This technique shows its strengths particularly in the deep pelvis, where the anatomical conditions are cramped and important nerve and vascular structures are located in a very confined space.
"Today, robot-assisted surgery is very important in the surgical treatment of rectal cancer, especially in specialized centers. In such facilities, where the robot is used with a high level of expertise, there are clear advantages over conventional procedures. One key aspect is the significantly higher precision. The use of an optical system with tenfold magnification and three-dimensional imaging gives surgeons an excellent overview of the surgical field. This is particularly relevant as the rectum is located in an anatomically narrow pelvic area where a clear view is of crucial importance. Another advantage lies in the superior fine motor skills of the robot-assisted instruments. The movements of the robotic arms are superior to those of the human hand in terms of precision, which leads to increased safety and control, particularly during more complex procedures in the small pelvis. Last but not least, robotic technology helps to treat surrounding structures as gently as possible. This can reduce the risk of complications, which ultimately also contributes to improved patient recovery," explains Prof. Dr. Rosenberg, adding important information regarding the risk of incontinence or the need for an artificial bowel outlet:
"The functions of the bowel, urinary bladder and sexual function in particular can be better preserved thanks to the gentle surgical technique. Nevertheless, there are situations in which a more radical surgical approach is necessary despite all the progress made. Whether a patient loses their continence depends largely on the location and stage of the tumor. If the tumor affects the sphincter muscle or the pelvic floor, healing must be the top priority. In such cases, the sphincter muscle cannot be preserved, which means that the patient will lose their continence after the operation. If the tumor is located just above the sphincter muscle, an attempt is always made to preserve continence, even if this is only possible with narrow safety margins. Thanks to improved surgical procedures, this is much more common today than it was a few years ago. Another factor influencing continence is the functionality of the nerve fibers responsible for stool control. If these are damaged by radiotherapy or during surgery, for example, they can also be impaired independently of the sphincter muscle. For this reason, the patient's faecal continence is carefully assessed before treatment begins. This assessment is essential, especially in older patients, who often already have a certain degree of weakness. The aim is to develop an individually appropriate treatment concept in close consultation with the patient, which offers oncological safety on the one hand, but also maintains quality of life as well as possible on the other."
For many patients, the topic of an artificial bowel outlet is initially associated with shame and fear. However, much has changed for the better in recent decades. "In only around 10 to 15 percent of cases of rectal cancer is a permanent artificial outlet necessary. And even if this diagnosis is initially a shock for most people, current studies and feedback from patients show that a very good quality of life can be achieved with today's care systems and professional care. Certified colorectal cancer centers offer optimal conditions for this. Specialized stoma therapists are available there, as are self-help groups to help those affected to cope. Talking to people who have had a similar experience can make a decisive contribution to reducing fears and enabling a largely normal life even with an artificial bowel outlet," emphasizes Prof. Dr. Rosenberg.
Molecular biological markers and personalized therapy approaches are becoming increasingly important in the modern treatment of rectal cancer and contribute significantly to making therapies more targeted, effective and at the same time gentler.
They make it possible to better understand tumor biology, create individual risk profiles and thus tailor treatment strategies more precisely to the individual patient. Central to this is the analysis of certain genetic and molecular changes within the tumor tissue. The markers provide valuable information on how a tumor will respond to certain therapies or what prognosis is associated with a certain molecular profile.
"Immunotherapy now also plays a major role in rectal cancer. We have already said that nowadays we examine every tumor using molecular genetics as soon as the diagnosis is made. And we now know that microsatellite-unstable rectal carcinomas respond very well to immunotherapy. Unfortunately, most rectal carcinomas are not microsatellite unstable - according to the literature, the probability is around five to ten percent. But if a tumor is microsatellite unstable, then we see that a cure can actually be achieved with immunotherapy alone. These patients then need neither chemotherapy nor surgery. This is something that has not been done for so long, but the development is rapid. These molecular markers are part of the concept of precision oncology. This means that today we can genetically analyze the tumor, i.e. create a genetic fingerprint, and select the appropriate drug therapy based on this. New treatment options are constantly coming onto the market that target precisely such genetic characteristics. Whether the whole thing will one day develop in such a way that rectal carcinomas are only treated oncologically, i.e. with medication - this is quite conceivable for certain subgroups. There are specific tumors for which this will certainly happen. But whether this really applies to all tumors remains to be seen. Of course we would like it to, but as a colorectal cancer specialist I don't have to worry about becoming unemployed at the moment," states Prof. Dr. Rosenberg.
The aim is for patients to be able to return to their normal everyday life quickly after the operation. They should be able to eat and drink again quickly and be able to move independently at an early stage.
"As a rule, patients stay in hospital for four to five days after the operation before being discharged home. Some patients undergo rehabilitation treatment after discharge, and depending on the stage of the tumor and the course of treatment, a decision is made as to whether further therapy is necessary. If no additional treatment is required, aftercare is provided, which has improved significantly in recent years. The aim of follow-up care is to detect recurrences at an early stage and to better treat treatment-related late effects. Imaging and diagnostics have developed considerably. In addition to computer tomography, high-resolution magnetic resonance imaging and positron emission tomography (PET) are also used today. PET uses radioactively labeled sugar particles that accumulate in tumor cells and thus enable early detection. A particularly new method is the examination of circulating tumor DNA in the blood, which enables us to detect tumor cells in the body and detect a possible recurrence at an early stage. Follow-up care is risk-adapted and stage-dependent, based on the current guidelines of the Swiss and German Surgical Societies. These specify the intervals at which check-ups should take place. Today, however, we not only attach importance to tumor aftercare, but also to the patient's quality of life. This is because it is known that patients often have problems with defecation after treatment for rectal cancer, especially after chemotherapy and radiation - a condition known as Low Anterior Resection Syndrome (LARS). For the treatment of patients suffering from such complaints, it is very important to have a specialized pelvic floor team to care for these patients. Another promising approach is gut microbiome therapy. There is initial evidence that targeted therapy of the microbiome can help to improve bowel function and digestion. This is a relatively new approach that is currently being pursued in research," explains Prof. Dr. Rosenberg on the follow-up measures.
Patients benefit from the fact that their treatment is not planned according to a rigid scheme, but individually, taking into account all available options. This structured, multidisciplinary approach is now considered the gold standard in oncological care and is crucial for successful treatment, especially in complex and advanced tumor stages.
In Switzerland, it is recommended to go for colon cancer screening, i.e. a colonoscopy, from the age of 50. If there are already cases of bowel cancer in the family, you should start screening at least ten years before the age at which your relative was diagnosed. Younger people should also be alert to blood in the stool, as this does not always indicate hemorrhoids, but may also indicate a serious illness. Bowel cancer is curable in many cases and there are now very good treatment options. Early colonoscopy remains the best preventive measure.
"However, most people shy away from this examination, usually because of shame or fear of pain. It has to be said that thanks to modern anesthetic techniques, the examination is no longer perceived as unpleasant. The only really unpleasant part is the preparation, which involves drinking a high-salt solution to cleanse the bowel," explains Prof. Dr. Rosenberg, focusing on the future at the end of our conversation:
"As far as the future is concerned, an incredible amount has happened in recent years and I am convinced that there will be many more advances in the coming years to enable us to treat patients with colorectal cancer even better. There is still a lot of room for improvement, especially in diagnostics. Currently, many treatments are based on magnetic resonance imaging, but in 20 to 30 percent of cases this is still not precise enough to determine the exact stage of the tumor. I would like to see better diagnostics that provide us with more precise information. There is also still a lot of potential in the identification of genetic changes that can be treated in a targeted manner. I am sure that considerable progress will also be made in this area. In the field of surgery, the focus remains on minimizing surgical trauma. We have already made great progress here in recent years, but there is still plenty of room for improvement so that operations can be performed even more gently. At Kantonspital Baselland, we are proud to be a certified colorectal cancer center with a performance mandate for highly specialized medicine. In Switzerland, only hospitals with this service mandate are allowed to operate on rectal cancer. We are one of the 15 hospitals in the country to have received this award. Our team is highly specialized and cares for patients with a lot of heart and professionalism. Our patients feel this, and we are convinced that this leads to better treatment and a better outcome."
Thank you very much, Professor Dr. Rosenberg, for this helpful information!
