Signs and symptoms of cancer


symptoms are changes in the body caused by the presence of cancer. They are usually caused by the effect of a cancer on the part of the body where it is growing, although the disease can cause more general symptoms such as weight loss or tiredness. There are more than 100 different types of cancer with a wide range of signs and symptoms which can manifest in different ways.

Signs and symptoms

Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. Cancer can be difficult to diagnose because its signs and symptoms are often nonspecific, meaning they may be general phenomena that do not point directly to a specific disease process.
In medicine, a sign is an objective piece of data that can be measured or observed, as in a high body temperature, a rash, or a bruise. A symptom, by contrast, is the subjective experience that may signify a disease, illness or injury, such as pain, dizziness, or fatigue. Signs and symptoms are not mutually exclusive, for example a subjective feeling of fever can be noted as sign by using a thermometer that registers a high reading.
Because many symptoms of cancer are gradual in onset and general in nature, cancer screening is a key public health priority. This may include laboratory work, physical examinations, tissue samples, or diagnostic imaging tests that a community of experts recommends be conducted at set intervals for particular populations. Screenings can identify cancers before symptoms develop, or early in the disease course. Certain cancers can be prevented with vaccines against the viruses that cause them.
Additionally, patient education about worrisome symptoms that require further evaluation is paramount to reduce morbidity and mortality from cancer. Symptoms that cause excess worry, symptoms that persist or are unexplained, and/or the appearance of several symptoms together particularly warrant evaluation by a health professional.

Mechanisms

Cancer may produce symptoms in one or more of the following ways:
  • Mass effect: An abnormal growth of tissue, or tumor, may compress nearby structures, causing pain, inflammation or disruption of function. Not all cancers produce solid tumors. Even benign cancers may have serious consequences if they appear in dangerous places, particularly the heart or brain. Small bowel obstructions caused by the growth of a tumor in the digestive system is another example of a 'space-occupying' consequence of cancer.
  • Loss of Function: Tumor cells may deplete normal cells of oxygen and nutrients, thus disrupting the function of a vital organ. Many tumors stimulate new blood vessel formation which serves to supply the tumor rather than the normal, healthy tissue. The abnormal function of cancer cells and reduced function of normal cells in a given organ may lead to organ failure.
  • * Increased Lactate Production: The Warburg Effect states that cancer cells in the presence of oxygen and glucose take a different path of energy production, diverting energy for biomass production to support tumor growth. This unique metabolism of cancer cells opens doors for possible cancer treatments including targeting lactate dehydrogenase and TCA intermediate production.
  • Paraneoplastic Syndromes: Some cancers produce "ectopic" hormones, particularly when tumors arise from neuroendocrine cells, causing a variety of endocrine imbalances. Examples include the production of parathyroid hormones by parathyroid tumors or serotonin by carcinoid tumors. In these cases, the cell types that produce these active small molecules proliferate malignantly and lose their responsiveness to negative feedback. Because hormones operate on tissues far from the site of production, paraneoplastic signs and symptoms may appear far from the tumor of origin.
  • * Venous Thromboembolism: Patients with certain types of cancers are at increased risk of blood clots due to excess production of clotting factors. These clots may disrupt circulation locally or dislodge and travel to the heart, lungs, or brain, and may be fatal. Symptoms of blood clots may include pain, swelling, warmth and in late stages, numbness, particularly in the arms and legs. Some cancer treatments may further increase this risk.
  • Effusions: Cancers may stimulate fluid shifts in the body and lead to extracellular collections of fluid. Breast and lung cancer, for example, often cause pleural effusions, or a buildup of fluid in the lining of the lungs. Abdominal cancers, including ovarian and uterine cancers, may cause fluid buildup in the abdominal cavity.

    Suspicious Symptoms

Symptoms of cancer may be nonspecific changes to the individual's sense of physical well-being, or may localize to a particular organ system or anatomic region.
The following symptoms may be manifestations of an underlying cancer. Alternatively, they may point to non-cancerous disease processes, benign tumors, or even be within the physiological range of normal. They may appear at the primary site of cancer or be symptoms of cancer metastasis, or spread. Further workup by a trained healthcare professional is required to diagnose cancer.

Constitutional Symptoms

  • Unexplained weight loss: Weight loss that is unintended and not explained by diet, exercise or other illness may be a warning sign of many types of cancer
  • Unexplained pain: Pain that persists, has no clear cause, and does not respond to treatment may be a warning sign of many types of cancers.
  • Unexplained tiredness or fatigue: Unusual and persistent tiredness may point to underlying illness, including blood cell cancers like leukemia or lymphoma
  • Unexplained night sweats or fever: These may be signs of an immune system cancer. Fever in children rarely points to malignancy, but may merit evaluation.

    Local Symptoms

Medical Workup

When patients present with "suspicious symptoms", healthcare providers follow specific guidelines or diagnostic pathways to evaluate for potential cancer. Healthcare professionals face challenges of distinguishing potentially serious symptoms as opposed to common benign conditions. Recent research in the UK has shown that some cancer types often require multiple consultations before confirmed diagnosis. Understanding these diagnostic challenges is crucial for both the healthcare providers and patients in navigating the cancer diagnostic process effectively and ethically.
A healthcare professional may pursue a formal diagnostic workup to evaluate symptoms of cancer. The tests ordered will depend upon the type of cancer suspected. These may include the following:
Modern approaches to cancer detection have evolved beyond traditional symptom recognition because of new technologies that can potentially identify cancers at earlier, more treatable stages.

Biomarkers

Cancer biomarkers provide crucial information about the different states of cells when transitioning from healthy to malignant cancer conditions. Recent research has shown proof of extensive biomarker technologies that show potential for early cancer detection, primarily focusing on minimally invasive approaches. These minimally invasive approaches are being developed to complement traditional screening methods. Essentially, these modern technologies and how they can detect cancer at earlier stages rather than traditional symptom recognition, could overall potentially improve survival rates.

Liquid Biopsies

Liquid biopsies allow for minimally invasive molecular characterizations of cancers through the detection of circulating different cells and their DNA.  This technology offers guidance on how these approaches could be beneficial for detection of early cancer symptoms before they actually develop, potentially leading to earlier intervention and improved outcomes.

Artificial Intelligence (AI)

Artificial intelligence applications in cancer diagnosis across clinical practices, while also keeping in mind the potential challenges, could be a beneficial impact for cancer screening and diagnostic processes. AI algorithms can analyze medical images, detect patterns in biomarker data, and help identify patients who are high-risk and may benefit from more extensive screening and applications like ai. These technologies could aim to assist healthcare professionals in screening asymptomatic patients, investigating symptomatic patients, and diagnosing cancer more effectively than just traditional methods alone.

Treatment-related and Secondary Symptoms

Cancers treatments may include surgery, chemotherapy, radiation therapy, hormonal therapy, targeted therapy and synthetic lethality, most commonly as a series of separate treatments. Some of these cancer therapies may produce treatment-related, or secondary, symptoms, including:
  • Pain
  • * Cancer pain may be caused by the tumor itself compressing nearby structures, impinging on nerves, or causing an inflammatory response. It may also be caused by therapies such as radiation or chemotherapy. With competent management, cancer pain can be eliminated or well controlled in 80% to 90% of cases, but nearly 50% of cancer patients in the developed world receive less than optimal care. Worldwide, nearly 80% of people with cancer receive little or no pain medication. Cancer pain in children and in people with intellectual disabilities is also reported as being under-treated.
  • Infection
  • Deep Vein Thrombosis
  • Pulmonary Embolism
  • Tumor Lysis Syndrome
  • Muscle Aches
Symptoms that require immediate treatment include:
  • Fever that is 100.4 °F or higher
  • Shaking chills
  • Chest pain or shortness of breath
  • Confusion
  • Severe headache with a stiff neck
  • Bloody urine