What is Cancer? Symptoms, Causes, and Treatment Methods

Cancer is a complex group of diseases that occurs when the genetic structure of cells in our body breaks down, causing them to multiply uncontrollably and invade surrounding healthy tissues. When the natural life cycle of cells is disrupted, these rogue cells form masses called tumors, preventing organs from performing their normal functions. Thanks to early diagnosis and the innovative treatment approaches offered by modern medicine, it is possible to halt this process and achieve a full recovery in many cases.

• Cancer is not a single disease but a broad spectrum of over 200 different types, named after the tissue from which they originate.
• According to World Health Organization (WHO) data, approximately 20 million new cases are diagnosed worldwide every year.
• The rate of complete healing (cure) is quite high for many types of cancer caught in their early stages.
• While genetic factors play a 5 to 10 percent role in the emergence of the disease, environmental factors are much more decisive.
• The diagnosis and treatment process requires the collaborative work of many branches, such as medical oncology, surgery, radiology, and pathology.

What is Cancer and How Does It Develop?

In a healthy human body, cells grow and divide in a specific order, and when the time comes, they die to make way for new cells. The most fundamental answer to the question of what cancer is lies in the disruption of this perfectly functioning cellular cycle. When the DNA in the cell nucleus is damaged by various factors, cells survive when they should die and continue to divide uncontrollably even when not needed. As a result of this accumulation, masses—namely tumors—are formed.

Tumors can be benign or malignant. Benign tumors generally grow slowly and do not spread to other tissues. However, malignant tumors, meaning cancer cells, have the ability to invade surrounding tissues and spread (metastasize) to distant parts of the body via the blood or lymph. Current data from the Ministry of Health and the World Health Organization show that while cancer cases are trending upwards globally, the rates of catching the disease at an early stage are rising at the same pace thanks to advances in diagnostic technologies.

Most Common Types of Cancer

Although cancer can develop from almost any tissue in our body, some types are seen much more frequently in society. While breast cancer and thyroid cancer are prominent in women, lung and prostate cancer are diagnosed more frequently in men. Additionally, large intestine (colorectal) and stomach cancers have a high incidence rate in both men and women. If you would like more detailed information on this topic, you can review our articles titled What is Colon Cancer? Symptoms and Treatment and Common Cancers in Men and Screening Tests.

What Causes Cancer and What Are the Risk Factors?

Although the causes of cancer cannot be pinned down to a single reason, DNA mutations lie at the root of the disease. While some of these mutations are inherited from a mother or father, the vast majority occur later in life due to the accumulation of environmental factors we are exposed to. Cancer risk factors refer to conditions that increase a person's likelihood of contracting the disease. Having a risk factor does not mean you will definitely get cancer, but it significantly raises the risk.

Environmental and Genetic Factors

The main risk factors playing a role in the development of the disease can be listed as follows:

• Tobacco and Tobacco Products: The largest preventable cause of lung, larynx, bladder, and oral cavity cancers.
• Diet and Obesity: Consuming highly processed foods, insufficient fiber intake, and excess weight pose a serious risk, especially for digestive system cancers.
• Radiation and UV Rays: Unprotected exposure to the sun's harmful ultraviolet rays paves the way for skin cancers.
• Hereditary Factors: A family history of early-age cancer or the presence of gene mutations like BRCA1 or BRCA2 increases the risk.
• Viruses and Infections: The Human Papillomavirus (HPV) can lead to cervical cancer, while Hepatitis B and C viruses can cause liver cancer. You can benefit from our article What is Cervical Cancer? Symptoms, HPV Vaccine, and Smear Test for information on HPV and ways to protect yourself.

What Are the Symptoms of Cancer?

Cancer symptoms vary greatly depending on where the tumor is located in the body, its size, and how much pressure it exerts on surrounding organs. Sometimes the disease gives no symptoms at all until it is very advanced, while other times the body may send certain signals early on. Reading these signals correctly and applying to a healthcare institution in a timely manner is the most critical step for the success of the treatment.

Early Warning Signs

Although different types of cancer cause different complaints, the general warning signs of cancer that should be taken into consideration are:

• Unexplained, rapid, and significant weight loss without dieting or exercising.
• Extreme fatigue and weakness that do not go away with rest or sleep and prevent the person from doing daily tasks.
• Palpable, usually painless, and hard lumps in the breast, neck, armpit, groin, or anywhere on the body.
• A stubborn cough or a thickening/hoarseness in the voice that lasts longer than three weeks and does not respond to treatment.
• Sudden changes in bowel habits, prolonged diarrhea or constipation, or the presence of blood in the stool or urine.
• Abnormal bleeding anywhere in the body, non-healing sores on the skin, or sudden changes in the shape or color of moles.

How is Cancer Diagnosed?

For a person applying to the hospital with a suspicion of cancer, the diagnostic process begins with a detailed physical examination and taking the patient's medical history. Depending on the nature of the complaints, the physician requests various blood tests, tumor markers, and imaging methods. Advanced imaging technologies such as Ultrasonography (USG), Computed Tomography (CT), Magnetic Resonance Imaging (MRI), and PET-CT play a major role in determining the location, size, and spread of masses in the body.

However, imaging methods alone are not sufficient to make a definitive diagnosis. A definitive diagnosis is made by examining a tissue or cell sample (biopsy) taken from the suspicious area under a microscope in a pathology laboratory. The pathology report determines whether the cells are cancerous, the type of cancer, and its growth rate (grade). This information is vital for staging the disease and creating the most appropriate treatment plan.

Cancer Treatment: Current Approaches

Cancer treatment is planned entirely on a personalized basis according to the type and stage of the disease, the patient's age, and their general health status. The main goal of treatment is to completely clear the cancer cells from the body, stop the spread of the disease, or, in advanced cases, improve the patient's quality of life by alleviating their complaints. Treatment planning is generally determined by a joint decision in tumor boards where surgery, medical oncology, and radiation oncology specialists come together.

Traditional treatment methods include surgical interventions to remove the tumor, chemotherapy using drugs to kill cancer cells, and radiotherapy aimed at shrinking the tumor with high-energy rays. These methods can be applied alone or combined with each other depending on the state of the disease.

Personalized Smart Treatments

The biggest revolution in the field of cancer treatment in recent years has been targeted therapies and immunotherapy. Targeted therapies, also known as smart drugs, directly attack the genetic targets that allow the cancer cell to grow and multiply without harming healthy cells. Immunotherapy, on the other hand, strengthens the patient's own immune system, enabling the body to recognize and fight cancer cells. These personalized treatments, applied by mapping the genetic profile of the tumor, significantly increase success rates.

Complications and Risk Groups

The cancer journey can bring about certain complications arising both from the nature of the disease itself and from the potent treatments applied. A growing tumor can put pressure on surrounding organs, leading to pain, respiratory distress, or digestive problems. Chemotherapy and radiotherapy applied during the treatment process can weaken the immune system, increasing susceptibility to infections, and cause side effects such as nausea, hair loss, and chronic fatigue.

In terms of risk groups, advancing age is one of the most important factors; the vast majority of cancer cases are seen in individuals aged 65 and over. However, heavy smokers, those with a first-degree relative with a history of breast, colon, or ovarian cancer, and people exposed to asbestos or heavy chemicals due to their profession are in the high-risk group. It is vital for individuals in this group to participate in regular screening programs (mammography, colonoscopy, etc.).

When Should You See a Doctor?

Noticing changes in your body and taking action in time is lifesaving. If any of the warning signs mentioned above last longer than two weeks, you should consult a healthcare institution without wasting time. Especially when you notice unexplained bleeding, sudden severe pain, or rapidly growing hard lumps on your body, you should not ignore the seriousness of the situation.

There may also be situations requiring emergency medical intervention. If a patient undergoing cancer treatment (especially chemotherapy) suddenly develops a fever of 38 degrees Celsius or higher, uncontrollable bleeding, sudden and severe shortness of breath, severe chest pain, or confusion, they should immediately apply to the nearest emergency room or call the 112 Emergency Call Center. During these periods when the immune system is suppressed, infections can create a life-threatening risk within hours.

The Cancer Journey at BHT CLINIC İstanbul Tema Hastanesi

At BHT CLINIC İstanbul Tema Hastanesi, we are aware of how sensitive the cancer diagnosis and treatment process is for our patients and their families. In our hospital, cancer diagnosis and treatment are evaluated in multidisciplinary tumor boards attended by all relevant branch specialists to create the most appropriate treatment plan for the individual. We stand by you at every stage of the process with our advanced imaging center, fully equipped pathology laboratory, and modern surgical units.

Our fully equipped emergency department and intensive care units, which provide 24/7 uninterrupted service, are ready for any acute developments and complications that may occur during the treatment process. In addition to the medical treatment of the disease, we aim to keep our patients' quality of life high with services such as psychological support and nutritional counseling. If you have doubts about your health or want to get your regular screenings done, you can speak with our specialist physicians by booking an appointment.

Frequently Asked Questions

Can cancer be completely cured?

Yes, it is possible to achieve a complete recovery (cure), especially in many types of cancer diagnosed at an early stage. The non-recurrence of the disease for a certain period after treatment (usually 5 years) is considered the most important indicator of a complete recovery.

Is cancer contagious?

No, cancer is not a disease that spreads from person to person. Sharing the same environment, hugging, using the same items, or breathing the same air does not transmit cancer. Only certain viruses that can lead to cancer, such as HPV or Hepatitis, are contagious.

Does having a biopsy cause cancer to spread?

In modern medicine, biopsy procedures are performed extremely safely using fine needles and special techniques that will not cause the tumor to spread. A biopsy is an indispensable procedure for a definitive diagnosis and accurate treatment planning, and it does not cause cancer to spread.

Is smart drug therapy applied to every patient?

Smart drugs (targeted therapies) are only effective in patients who have specific genetic mutations or cellular targets in their tumors. Therefore, before starting treatment, genetic tests are performed on the tissue sample taken to determine whether the patient is suitable for this treatment.

When should cancer screening tests start?

The starting age for screening tests varies depending on the type of cancer and the person's risk factors. Generally, mammography is recommended for women at age 40 and a smear test at age 21; a colonoscopy is recommended for both men and women at age 50. However, for those with a family history, these ages may be brought forward.

This article is for informational purposes only; please be sure to consult your physician for diagnosis and treatment.