Robotic surgery for rectal cancer: personalised treatment and surgical precision

When faced with a diagnosis of rectal cancer, understanding the treatment options helps you make sense of the decisions that lie ahead. Will surgery be necessary? Under what circumstances is it possible to preserve the rectum? Can the procedure be carried out using robotic surgery?

Professor Julio García Aguilar, head of the Digestive Tumours Unit in the Department of Surgical Oncology at the Publio Cordón Memorial Hospital, has focused much of his clinical and research work on advances in the surgical treatment of rectal cancer, ranging from minimally invasive and robotic surgery to organ-preservation strategies.

As the specialist explains, technology is just one of the decisions that form part of the treatment: ‘When a patient is diagnosed with rectal cancer, it is understandable that they should ask whether they can have robotic surgery. To answer this, we must first gain a thorough understanding of the tumour and determine what treatment is required, whether surgery is necessary, and when is the right time to carry it out.”

This initial assessment allows each technique to be placed within a broader strategy tailored to the characteristics of the disease and the patient.

Why rectal surgery requires particular precision

The rectum is the final section of the large intestine and is situated within the pelvis. In this relatively narrow space, various organs coexist and nerves related to urinary and sexual functions run through it. When the tumour is very close to the anus, its relationship with the sphincters – the muscles that help control the passage of stools – must also be assessed.

The operation may require the removal of the affected segment of the rectum together with the mesorectum, the fatty tissue surrounding it which contains blood vessels and lymph nodes. In certain tumours, particularly those of the middle and lower rectum, a total mesorectal excision is performed: the removal of this tissue along its anatomical boundaries. The aim is to achieve tumour-free margins; in other words, to ensure that the edges of the excised tissue do not contain any cancer cells.

This proximity between the tumour and structures vital for everyday life explains the demands placed on the operation. In addition to treating the cancer, the planning must take into account how to preserve, wherever possible, bowel, urinary and sexual functions.

That is why, as Professor García Aguilar emphasises, surgical precision has a dimension that goes beyond the mere removal of the tumour: ‘In rectal surgery, we must always consider these two dimensions. The primary objective is to treat the cancer effectively, but we must also endeavour to preserve, wherever possible, structures that underpin functions vital to the patient’s daily life.”

It is precisely in an anatomy of this nature that certain features of robotic surgery can prove particularly useful.

What robotic surgery offers

In a robotic procedure, the surgeon controls the instruments from a console; the platform does not operate autonomously. The surgeon’s movements are transmitted to the instruments inserted into the body through small incisions.

The system provides a magnified three-dimensional image and features articulated instruments that can be directed in different directions. These features help surgeons to work in depth and perform precise movements in areas where space is limited, such as around the rectum.

García Aguilar summarises the usefulness of these tools whilst emphasising the importance of the team’s expertise: ‘The robotic platform can assist us with some of the most delicate stages of the operation. Using it requires a precise knowledge of anatomy, specific training and experience: technology and the team’s expertise must advance hand in hand’.

Experience is not a secondary consideration. Learning these techniques has also formed part of the specialist’s research. Professor García Aguilar is co-author of a study on the learning curve for robotic rectal surgery, published in *Surgical Endoscopy*, which analysed the progression of surgical expertise across a series of procedures.

It is also important to distinguish between the method of accessing the body and the operation performed inside it. A minimally invasive procedure must still be effective oncological surgery. Small incisions do not alter the need to remove the tumour properly, nor do they eliminate the risks inherent in the procedure.

Various surgical options for personalised treatment

Open surgery, laparoscopy and robotic surgery are among the options available for treating rectal cancer. The choice depends on the characteristics of the tumour, the patient’s anatomy, their clinical condition and the procedure that needs to be carried out.

Rather than the name of the technique, what matters most to the patient is understanding what procedure they need and why it is being proposed. In this regard, Professor García Aguilar emphasises the importance of also explaining the functional implications and the expected recovery: ‘When we propose a procedure, we must explain to the patient what we need to remove, what the chances are of preserving function, and what the recovery might be like. Understanding these aspects helps them grasp why we recommend a particular operation, beyond the name of the technique.”

Clinical research provides information to guide these decisions. The REAL trial, published in JAMA in 2025, studied the outcomes of robotic and laparoscopic surgery in patients with mid- and lower-rectal tumours. In addition to cancer control and survival, it assessed urinary, sexual and bowel function following the procedure.

Studies of this kind broaden the way we assess surgical outcomes: it is not only important to control the disease, but also to understand its potential impact on the patient’s life afterwards. The evidence helps in decision-making, but it does not replace the individual assessment of each case.

How rectal cancer treatment is planned

Planning begins with confirming the diagnosis via a biopsy and assessing the extent of the disease. An MRI scan of the pelvis provides a detailed picture of how the tumour relates to nearby tissues and offers important information for deciding on treatment.

Some patients may undergo surgery straight away. In other cases, chemotherapy, radiotherapy or a combination of both is administered first. Depending on the situation, these treatments aim to shrink the tumour, make local treatment easier and reduce the risk of relapse.

But planning does not end when treatment begins. The response to treatment provides new information and may influence subsequent decisions. As García Aguilar explains: ‘The response to treatment also provides us with information. Once treatment is complete, we must re-examine the patient and review the scans to see what has changed. This new assessment may influence the procedure we propose and, in certain cases, open up the possibility of preserving the rectum.”

In this way, the treatment plan can be adapted as the disease progresses.

Decisions are made with the involvement of the relevant specialist teams. At the Publio Cordón Memorial Hospital, the assessment of gastrointestinal tumours involves multidisciplinary planning and takes into account both the extent of the disease and the characteristics of the tumour, as well as the available treatment options.

Rectal preservation: an option for certain patients

Following pre-surgical treatment, some tumours show a particularly favourable response. When clinical examination, endoscopy and imaging tests reveal no detectable signs of the tumour, this is referred to as a complete clinical response.

This outcome may allow a rectal-preserving strategy to be considered in carefully selected patients.

The strategy, known as ‘watch and wait’ or active surveillance, involves initially avoiding rectal resection and maintaining specialised follow-up. The absence of tumour detection in examinations does not guarantee that all cancer cells have disappeared; therefore, surveillance is an essential component of this approach.

Professor García Aguilar’s scientific contribution is particularly significant in this field. He was the lead author of the initial publication of the OPRA trial on organ preservation, which appeared in the *Journal of Clinical Oncology* in 2022. The study investigated different sequences of chemotherapy and radiotherapy before assessing the need for surgery in patients with locally advanced rectal cancer.

The long-term results of the OPRA trial showed that a significant proportion of participants were able to preserve their rectum. In the group that first received combined chemotherapy and radiotherapy, followed by further chemotherapy, the estimated rate of patients not requiring total mesorectal excision at five years was 54 per cent.

This figure relates to a specific strategy within the study and cannot be applied as an individual expectation to all people with rectal cancer. It does, however, demonstrate why response to treatment has taken on an increasingly important role in decision-making.

As García Aguilar points out, the change lies in incorporating the possibility of preserving the organ without losing sight of the demands of cancer treatment: ‘One of the major changes in rectal cancer is that today we do not think solely about how best to remove the tumour. We also try to identify those patients in whom, following an excellent response to radiotherapy and chemotherapy, we can preserve the rectum. But that requires very rigorous selection and equally rigorous monitoring.”

Follow-up as part of treatment

Active surveillance involves regular clinical examinations, endoscopies and imaging tests. Its aim is to detect any tumour regrowth as early as possible and to assess the necessary course of action. It does not involve postponing a decision without monitoring, but rather following a structured care programme.

The OPRA follow-up study showed that the vast majority of local recurrences occurred during the first few years, particularly in the first two years. This finding explains the frequency of check-ups at that stage.

The professor emphasises precisely that, when the decision is made to preserve the rectum, surveillance is not a supplementary measure, but part of the treatment itself: ‘Preserving the rectum requires a very careful assessment of the response to treatment and explaining to the patient what follow-up entails. When this option is appropriate, monitoring becomes an essential part of care, with scheduled check-ups and the possibility of intervening if disease is detected again’.

The response obtained, the patient’s ability to adhere to the follow-up programme, and the patient’s preferences all form part of the assessment. When the necessary conditions for preserving the organ are not met, surgery remains part of the recommended treatment.

A treatment plan tailored to each individual

Robotic surgery and rectal-preserving strategies address different needs within the treatment of the same disease. The former may facilitate certain procedures; the latter allow, in selected patients, an alternative to immediate removal of the organ to be considered.

Both form part of a broader development: gaining a better understanding of the tumour and the therapeutic options available in order to tailor treatment to each individual.

For the patient, this assessment must be translated into a clear explanation: what treatment is recommended, what the expected outcomes are, what the risks are, and how recovery and follow-up will be managed.

Professor García Aguilar summarises this approach to the treatment of rectal cancer as follows: ‘Our aim is for every patient to receive the treatment they need, whilst prioritising both disease control and their quality of life. Technology and research are meaningful when they help us to meet these needs.’

Information about this content

This article is for informational purposes only and is not a substitute for an individual medical assessment. The information has been compiled from scientific sources and the specialist’s clinical experience, with the aim of facilitating an understanding of the diagnosis and the various treatment options.

Each case must be assessed on an individual basis by a specialist medical team, taking into account the characteristics of the patient and the condition.

The information in this article is provided for general awareness and does not replace an individualised medical assessment.