Theranostics: How the Combination of Diagnostics and Treatment Can Personalize Cancer Treatment Approaches

The Ministry of Health has started distributing nine high-tech medications intended for cancer treatment within the Brazilian public network. This initiative is part of a governmental plan focused on expanding access to oncological therapies in the country.

The drugs cover 13 clinical indications, covering treatments for high-incidence cancers such as breast, prostate, and lung cancer, as well as lymphomas. Initially, it is expected to benefit more than 116 thousand patients across 20 health units located in 17 states, with the goal of covering the entire public network by the end of the year.

Maria Ignez Braghiroli, an oncologist specializing in gastrointestinal tract tumors at Oncologia D’Or and a member of the Gastrointestinal Tumor Group at the State Cancer Institute of São Paulo (Icesp), detailed the impact of including these new medications in the Unified Health System (SUS), their applications, and the necessary care during treatment.

Among the introduced medications are abemaciclibe, used in breast cancer treatment, and pazopanib, indicated for advanced stages of kidney cancer. These therapies offer more treatment options but require rigorous medical monitoring and specific care.

According to Maria Ignez, abemaciclibe works by inhibiting proteins that stimulate tumor cell proliferation. It is used in a type of breast cancer that is hormone receptor positive. The treatment is often combined with hormonal therapy and, because it is oral, allows the patient to administer it at home, following prescribed times and doses, usually twice a day.

The oncologist warned that the most common side effect is diarrhea, especially in the first weeks, requiring constant monitoring. Additionally, it can cause fatigue and nausea in some individuals.

Regarding pazopanib, Maria Ignez clarified that it interferes with processes that promote tumor growth and the formation of blood vessels that nourish cancerous cells. It is an anti-angiogenic targeted therapy, released by the SUS for renal cell cancer, because it blocks signals that drive tumor growth and vascularization, restricting nutrient supply.

The use of pazopanib requires continuous vigilance, especially due to possible changes in blood pressure and liver function. Hypertension can occur even in patients without prior history, and liver changes must be checked through periodic blood tests. The doctor added that despite the increased risk of bleeding, the general tolerance of the drug is reasonable when compared to traditional chemotherapy.

Another novelty is the inclusion of trastuzumab, already used in certain breast tumors, to treat specific cases of stomach and gastroesophageal junction cancer. This indication is linked to the presence of the HER2 protein, whose amplification occurs in a percentage of gastric tumors.

Braghiroli explained that the efficacy of trastuzumab in this new context was investigated in studies over ten years ago. Initially, the drug was used in breast tumors with HER2 amplification, and a 2010 study demonstrated its benefit in treating gastric tumors with this molecular characteristic. Since then, it has been approved in combination with chemotherapy for specific tumors.

Research continues to advance, with recent studies, such as one from 2023, showing the benefit of combining immunotherapy with this combination. The doctor emphasized that for the SUS, this is a significant advance, given that this medication has proven efficacy for some time.

The list provided by the Ministry of Health includes treatments for various types of cancer, whose indications depend on the characteristics and stage of the disease. Abiraterone, for example, acts on hormonal stimulation, a key mechanism in prostate cancer progression. By reducing testosterone production, it helps control the disease, even in areas where conventional hormonal treatments were not fully effective.

According to the specialist, abiraterone is used when standard hormonal blockade methods fail, being a well-established treatment in clinical practice. However, not all treatments are universal; the indication for some depends on detecting specific genetic or protein alterations in the tumor cells, making laboratory tests crucial for therapeutic decisions.

Gefitinib, used against certain lung tumors, is an example of this. Although it is an established treatment, it is only indicated if the tumor presents a mutation in the EGFR gene, conferring sensitivity to the therapy. This alteration is confirmed by a molecular test performed on a tumor sample collected during diagnosis.

In addition to the provision of medications, the Ministry of Health has begun distributing 400 thousand fecal immunochemical tests to Brazilian states and capitals. This action aims to intensify the prevention and early diagnosis of intestinal cancer, targeting men and women between 50 and 75 years old.

The test detects traces of blood in the feces, even those invisible to the naked eye, which may indicate existing polyps or tumors. Early identification allows referral for complementary exams, such as colonoscopy, which allows visualization of the intestine and removal of polyps. Several medical societies recommend this preventive screening.

The fecal immunochemical test serves as the first phase of this investigation: a positive result directs the individual to colonoscopy to determine the source of the bleeding and evaluate lesions. Other improvements in the public network include the implementation of cervical cancer screening with DNA tests and federal funding for video-thoracic oncological surgeries, which allow for faster recovery.

Despite the expansion of these initiatives, the main challenge for the SUS remains ensuring that the availability of medications, exams, and procedures translates into effective care, guaranteeing complete patient follow-up throughout the entire treatment process.

Melatonin, a substance often used by people to combat jet lag or improve sleep, is attracting the attention of scientists as a possible auxiliary agent in the fight against glioblastoma—one of the most dangerous types of brain cancer.

Glioblastoma is a primary malignant tumor of the brain, most often found in adults, and is one of the most difficult cancers to treat. Its characteristic feature is that it does not grow as a compact ball that can be surgically removed; instead, it resembles weed roots, penetrating between neurons and spreading microscopic branches into healthy tissue. Because of this, even after visible parts are removed by neurosurgeons, hidden cells almost always remain.

To combat these remaining cells after surgery, radiation therapy and the drug temozolomide are used, which has been recognized as the basis of treatment since 2005 due to a large clinical study. However, the tumor is prone to recurrence, meaning regrowth.

To understand the cause of recurrences, it is necessary to examine the mechanism of action of temozolomide. This drug acts on DNA, which serves as the instruction for cell division, by 'smudging' key words. If there are too many such 'smudges,' the cell cannot copy its instructions and dies. Nevertheless, many cancer cells possess their own 'corrector'—the enzyme O6-methylguanine-DNA methyltransferase (MGMT)—capable of eliminating the most harmful damage. When the gene coding for this protein is suppressed, the effectiveness of chemotherapy is higher; when it is active, much of the anti-tumor effect is lost.

Furthermore, the tumor is heterogeneous: among its cells are those with stem cell properties, meaning they can self-reproduce and create new, treatment-resistant cancer cells, like embers igniting a fire. This heterogeneity explains why treatment may destroy many cells but leave others capable of causing the disease to return. This also justifies interest in combining interventions: if a substance hinders the survival mechanisms of cancer cells, it can increase the effectiveness of the damage inflicted by chemotherapy. This is where melatonin comes in.

Our brain produces melatonin at dusk, using it as a biological clock signaling the body's need for rest. But its function is not limited to this. Simultaneously, it participates in inflammation processes, the body's defense mechanisms, and the regulation of cellular energy. Interestingly, melatonin acts differently in different locations. In healthy cells, it usually acts as a shield against oxidative damage. In some cancer cells, conversely, it disrupts the energy production mechanism. In a study with glioblastoma cells obtained from patients, it was observed that melatonin alters the energy production and metabolic regulation of these cells, leading to their death. Other studies suggest that it also modifies the interaction between the tumor and the immune system.

The reason for this dual nature lies in the fact that cancer cells exist at the limit of capabilities: they grow rapidly, consume a lot of energy, and depend on a fragile balance. A stimulus that a healthy cell absorbs without problems can destabilize a cancer cell. The idea of combining these two molecules is simple: while temozolomide damages the 'instructions' for cancer cell reproduction, melatonin prevents its defense and repair. Their combination is like a simultaneous strike on the building and its maintenance staff.

This idea is confirmed in laboratory settings. A 2025 study showed that in glioblastoma cell cultures, the combined effect exceeded the simple sum of the effects of each substance separately. The mixture suppressed signals that help the tumor survive and become inflamed, while also activating its self-destruction mechanisms. Furthermore, melatonin slowed tumor growth in mice. However, there is an important nuance: these tumors were implanted under the animal's skin, not in the brain. The brain is a fortress protected by a barrier that prevents many substances from entering. What works on the side of a mouse's brain may not work inside the skull.

Another study conducted in 2018 concerned residual cells with stem cell properties: melatonin made them more sensitive to temozolomide, although the effect varied greatly depending on the experimental model.

Treating a brain tumor is not just about eliminating it; it is crucial to preserve memory, mood, and the ability to lead a full life. Unfortunately, chemotherapy also negatively affects the healthy brain. In this regard, there is another promising path. In mice without tumors that received temozolomide, melatonin prevented depressive behavior and weakened changes in new neuron formation, although it did not prevent anxious behavior. This is an interesting result, but it needs to be proven in humans, and we must remember that protecting healthy tissue does not automatically mean protecting the tumor.

By this point, it is easy to think that since melatonin can be bought at the pharmacy, why not take it immediately? There are at least three reasons why this should not be done. Firstly, there is dosage. Many experiments use concentrations hundreds of thousands of times higher than the natural levels achieved by our body at night. It is unknown whether a pill can reach similar levels inside the brain tumor, and whether attempting this is safe.

Secondly, there is very little human data. The main clinical study was published in 1996: a small test with 30 patients showed that those who took melatonin along with radiation therapy had better survival rates after one year. This is a noteworthy fact, but it is based on a very small group of patients, predates the advent of temozolomide, and does not answer today's question.

Thirdly, adding any substance to oncological treatment can have unforeseen consequences. Therefore, patients undergoing treatment should not take melatonin for this purpose without prior consultation with the medical team and never as a substitute for prescribed therapies.

All this means that melatonin is false hope? No. It means that a good idea has reached the most difficult test. The next step is clinical trials, which will first determine the safe dose and penetration level into the tumor, and then compare standard treatment with treatment involving melatonin. And it will not be enough to measure patient lifespan; the quality of their life, including memory and emotional state, will need to be assessed. However, there is an additional obstacle. Since melatonin is a cheap and non-patented molecule, commercial incentives to fund these studies are minimal. In this case, independent research funded by public funds is necessary. Perhaps in a few years, the hormone that helps us sleep will also help chemotherapy work better. To find out, we need not just good results in cell cultures, but patients, rigor, and time.

Breast cancer is traditionally associated with women, but this disease is also possible in men, although cases among them are significantly rarer. Nevertheless, it is extremely important to know about the symptoms of this disease. The AIIMS Bhopal medical institute conducted an awareness campaign on this issue.

As part of Breast Cancer Awareness Month, which takes place at the institute from October 1st to 31st, various educational events are being held. These programs aim to inform men about possible signs of the disease and strongly recommend timely medical examination.

Men may also experience the formation of lumps in the chest, which can be located even near the nipples. Any such changes should not be ignored. Other potential signs include nipple retraction, skin changes, and unusual discharge from the nipple. A lump in the armpit area is also one of the symptoms. If these changes persist for a long time, a doctor should be consulted for examination.

According to information from AIIMS Bhopal, not all detected symptoms indicate the presence of cancer. There are other reasons for the appearance of lumps in the chest. However, any new changes require attention, and if they persist constantly, consulting a specialist becomes necessary. Timely diagnosis allows the disease to be detected at an early stage.

A history of breast cancer in the family plays a significant role, as it can influence the probability of developing the disease. Some genetic changes can also increase the risk. In such cases, increased vigilance is required, and any abnormal changes should be discussed with a doctor and necessary examinations should be undergone.

The level of awareness about this disease among men remains low, and many tend to ignore symptoms or hesitate to seek help. AIIMS Bhopal is actively promoting awareness, urging men not to be shy about seeking support. It is important not to hide any changes in the breasts or nipples, but instead to consult a doctor in a timely manner. Any new changes should be noticed, and if the symptoms persist, an examination must be conducted. Breast cancer is not exclusively a female problem, so men should be aware of the symptoms.