Signs and symptoms which may suggest lung cancer include:

- Respiratory symptoms: coughing, coughing up blood, wheezing, or shortness of breath

- Systemic symptoms: weight loss, weakness, fever, or clubbing of the fingernails

- Symptoms due to the cancer mass pressing on adjacent structures: chest pain, bone pain, superior vena cava obstruction, or difficulty swallowing

If the cancer grows in the airways, it may obstruct airflow, causing breathing difficulties. The obstruction can lead to accumulation of secretions behind the blockage, and predispose to pneumonia.

Depending on the type of tumor, paraneoplastic phenomena—symptoms not due to the local presence of cancer—may initially attract attention to the disease. In lung cancer, these phenomena may include hypercalcemia, syndrome of inappropriate antidiuretic hormone (SIADH, abnormally concentrated urine and diluted blood), ectopic ACTH production, or Lambert–Eaton myasthenic syndrome (muscle weakness due to autoantibodies). Tumors in the top of the lung, known as Pancoast tumors, may invade the local part of the sympathetic nervous system, leading to Horner's syndrome (dropping of the eyelid and a small pupil on that side), as well as damage to the brachial plexus.

Many of the symptoms of lung cancer (poor appetite, weight loss, fever, fatigue) are not specific. In many people, the cancer has already spread beyond the original site by the time they have symptoms and seek medical attention. Symptoms that suggest the presence of metastatic disease include weight loss, bone pain and neurological symptoms (headaches, fainting, convulsions, or limb weakness). Common sites of spread include the brain, bone, adrenal glands, opposite lung, liver, pericardium, and kidneys. About 10% of people with lung cancer do not have symptoms at diagnosis; these cancers are incidentally found on routine chest radiography.

Many of the symptoms of NSCLC can be signs of other diseases, but having chronic or overlapping symptoms may be a signal of the presence of the disease. Some symptoms are indicators of less advanced cases while some may signal that the cancer has spread. Some of the symptoms of less advanced cancer include chronic cough, coughing up blood, chest pain, hoarseness, shortness of breath, wheezing, chest pain, weight loss, and loss of appetite. A few more symptoms associated with the early progression of the disease are feeling weak, being very tired, having trouble swallowing, swelling in the face or neck, and continuous or recurring infections like bronchitis or pneumonia. Signs of more advanced cases include bone pain, nervous system changes (headache, weakness, dizziness, balance problems, seizures), jaundice, lumps near the surface of the body, numbness of extremities due to Pancoast Syndrome, and nausea, vomiting and constipation brought on by hypercalcemia. Some more of the symptoms that indicate further progression of the cancer include shortness of breath, superior vena cava syndrome, trouble swallowing, large amounts of mucus, weakness, fatigue, and hoarseness.

It most often arises centrally in larger bronchi, and while it often metastasizes to locoregional lymph nodes (particularly the hilar nodes) early in its course, it generally disseminates outside the thorax somewhat later than other major types of lung cancer. Large tumors may undergo central necrosis, resulting in cavitation. A squamous-cell carcinoma is often preceded for years by squamous-cell metaplasia or dysplasia in the respiratory epithelium of the bronchi, which later transforms to carcinoma in situ.

In carcinoma in situ, atypical cells may be identified by cytologic smear test of sputum, bronchoalveolar lavage or samples from endobronchial brushings. However, squamous-cell carcinoma in situ is asymptomatic and undetectable on X-ray radiographs.

Eventually, it becomes symptomatic, usually when the tumor mass begins to obstruct the lumen of a major bronchus, often producing distal atelectasis and infection. Simultaneously, the lesion invades into the surrounding pulmonary substance. On histopathology, these tumors range from well differentiated, showing keratin pearls and cell junctions, to anaplastic, with only minimal residual squamous-cell features.

Pulmonary neuroendocrine tumors are neuroendocrine tumors localized to the lung: bronchus or pulmonary parenchyma.

Pulmonary neuroendocrine tumors include a spectrum of tumors from the low-grade typical pulmonary carcinoid tumor and intermediate-grade atypical pulmonary carcinoid tumor to the high-grade pulmonary large cell neuroendocrine carcinoma (LCNEC) and pulmonary small cell carcinoma (SCLC), with significant clinical, epidemiologic and genetic differences.

Non-small-cell lung carcinoma (NSCLC) is any type of epithelial lung cancer other than small cell lung carcinoma (SCLC). NSCLC accounts for about 85% of all lung cancers. As a class, NSCLCs are relatively insensitive to chemotherapy, compared to small cell carcinoma. When possible, they are primarily treated by surgical resection with curative intent, although chemotherapy is increasingly being used both pre-operatively (neoadjuvant chemotherapy) and post-operatively (adjuvant chemotherapy).

Small-cell carcinoma of the lung usually presents in the central airways and infiltrates the submucosa leading to narrowing of bronchial airways. Common symptoms include cough, dyspnea, weight loss, and debility. Over 70% of patients with small-cell carcinoma present with metastatic disease; common sites include liver, adrenals, bone, and brain.

Due to its high grade neuroendocrine nature, small-cell carcinomas can produce ectopic hormones, including adrenocorticotropic hormone (ACTH) and anti-diuretic hormone (ADH). Ectopic production of large amounts of ADH leads to syndrome of inappropriate antidiuretic hormone hypersecretion (SIADH).

Lambert-Eaton myasthenic syndrome (LEMS) is a well-known paraneoplastic condition linked to small-cell carcinoma.

Squamous-cell carcinoma (SCC) of the lung is a type of non-small-cell lung carcinoma and is more common in men than in women. It is closely correlated with a history of tobacco smoking, more so than most other types of lung cancer. According to the Nurses' Health Study, the relative risk of SCC is approximately 5.5, both among those with a previous duration of smoking of 1 to 20 years, and those with 20 to 30 years, compared to never-smokers. The relative risk increases to approximately 16 with a previous smoking duration of 30 to 40 years, and approximately 22 with more than 40 years.

Lung cancer, also known as lung carcinoma, is a malignant lung tumor characterized by uncontrolled cell growth in tissues of the lung. This growth can spread beyond the lung by the process of metastasis into nearby tissue or other parts of the body. Most cancers that start in the lung, known as primary lung cancers, are carcinomas. The two main types are small-cell lung carcinoma (SCLC) and non-small-cell lung carcinoma (NSCLC). The most common symptoms are coughing (including coughing up blood), weight loss, shortness of breath, and chest pains.

The vast majority (85%) of cases of lung cancer are due to long-term tobacco smoking. About 10–15% of cases occur in people who have never smoked. These cases are often caused by a combination of genetic factors and exposure to radon gas, asbestos, second-hand smoke, or other forms of air pollution. Lung cancer may be seen on chest radiographs and computed tomography (CT) scans. The diagnosis is confirmed by biopsy which is usually performed by bronchoscopy or CT-guidance.

Avoidance of risk factors, including smoking and air pollution, is the primary method of prevention. Treatment and long-term outcomes depend on the type of cancer, the stage (degree of spread), and the person's overall health. Most cases are not curable. Common treatments include surgery, chemotherapy, and radiotherapy. NSCLC is sometimes treated with surgery, whereas SCLC usually responds better to chemotherapy and radiotherapy.

Worldwide in 2012, lung cancer occurred in 1.8 million people and resulted in 1.6 million deaths. This makes it the most common cause of cancer-related death in men and second most common in women after breast cancer. The most common age at diagnosis is 70 years. Overall, 17.4% of people in the United States diagnosed with lung cancer survive five years after the diagnosis, while outcomes on average are worse in the developing world.

Pulmonary neuroendocrine tumor are classified according to tumoral grade:

- Low grade pulmonary neuroendocrine tumor: Typical pulmonary carcinoid tumour (TC; low-grade);

- Intermediate-grade pulmonary neuroendocrine tumor: Atypical pulmonary carcinoid tumour (AC; intermediate-grade)

- High-grade pulmonary neuroendocrine tumor

- Small cell lung cancer (SCLC)

- Large cell neuroendocrine carcinoma (LCNEC of the lung)

Low-grade nodular neuroendocrine proliferations ≥ 0.5 cm are classified as carcinoid tumors and smaller ones are called pulmonary tumorlets.

When neuroendocrine cell hyperplasia and tumorlets are extensive, they represent the rare preinvasive lesion for carcinoids known as "diffuse idiopathic pulmonary neuroendocrine cell hyperplasia".

Both LCNEC and SCLC can demonstrate histologic heterogeneity with other major histologic types of lung carcinoma, such as pulmonary adenocarcinoma or pulmonary squamous cell carcinoma, but is not characteristic of TC or AC.

Small-cell carcinoma (also known as "small-cell lung cancer", or "oat-cell carcinoma") is a type of highly malignant cancer that most commonly arises within the lung, although it can occasionally arise in other body sites, such as the cervix, prostate, and gastrointestinal tract. Compared to non-small cell carcinoma, small cell carcinoma has a shorter doubling time, higher growth fraction, and earlier development of metastases.

Symptoms of Hypopharyngeal Cancer include:

- Swollen lymph nodes in the neck (first sign of a problem in half of all patients)

- Sore throat in one location that persists after treatment

- Pain that radiates from the throat to the ears

- Difficult or painful swallowing (often leads to malnutrition and weight loss because of a refusal to eat)

- Voice changes (late stage cancer)

Hypopharyngeal cancer is a disease in which malignant cells grow in the hypopharynx (the area where the larynx and esophagus meet).

It first forms in the outer layer (epithelium) of the hypopharynx (last part of the pharynx), which is split into three areas. Progression of the disease is defined by the spread of cancer into one or more areas and into deeper tissues.

This type of cancer is rare. Only about 2,500 cases are seen in the US each year. Because of this, Hypopharyngeal Cancer is difficult to catch in its earliest stages and has one of the highest mortality rates of any head and neck cancer.

The possible signs of oropharyngeal cancer are:

- A sore throat that persists

- Pain or difficulty with swallowing

- Unexplained weight loss

- Voice changes

- Ear pain

- A lump in the back of the throat or mouth

- A lump in the neck

- A dull pain behind the sternum

- Cough

Symptoms of cancer in dogs may include:

- Lumps (which are not always malignant, but should always be examined by a vet)

- Swelling

- Persistent sores

- Abnormal discharge from any part of the body

- Bad breath

- Listlessness/lethargy

- Rapid, often unexplained weight loss

- Sudden lameness

- Offensive odor

- Black, tarry stools (a symptom of ulcers, which can be caused by mast cell tumors)

- Decreased or loss of appetite

- Difficulty breathing, urinating or defecating

Oropharyngeal cancer is a disease in which cancer form in the tissues of the throat (oropharynx). The oropharynx is the middle part of the throat that includes the base of the tongue, the tonsils, the soft palate, and the walls of the pharynx. Oropharyngeal cancers can be divided into two types, HPV-positive, which are related to human papillomavirus infection, and HPV-negative cancers, which are usually linked to alcohol or tobacco use.

Most cancers typically present as a single primary tumor. Over the course of time—particularly if the primary tumor is left untreated—smaller "satellite" tumors will appear at other places in the body, a phenomenon known as metastasis. Less commonly, a metastatic tumor is found first; but in most such cases, the primary tumor can then be located via examination and testing. Rarely (3-5% of the time), the primary tumor cannot be found because it is too small, or because it has regressed due to immune system activity or other factors. In such situations a diagnosis of cancer of unknown primary origin (CUP) is made.

CUP usually comes to attention because of masses or swellings found somewhere in the body, either by physical examination or on medical imaging performed for another indication. The disease typically develops rapidly, and metastases may occur in places in the body that are otherwise unusual. Comprehensive physical examination is part of the process to identify a possible primary source of cancer; this should include the breasts, lymph nodes, the skin, external genitals, as well as an internal examination of the rectum and of the pelvic organs.

The location of metastases may be a clue as to the underlying source, even if this cannot be found on investigations. For instance, a woman in whom there is axillary lymphadenopathy (swelling in the lymph nodes of the armpit) it is likely that the cancer originated in the breast, and men with lymph node deposits in the mediastinum of the chest and/or retroperitoneal space of the abdomen may have a germ cell tumor.

The most common cancers in children are (childhood) leukemia (32%), brain tumors (18%), and lymphomas (11%). In 2005, 4.1 of every 100,000 young people under 20 years of age in the U.S. were diagnosed with leukemia, and 0.8 per 100,000 died from it. The number of new cases was highest among the 1–4 age group, but the number of deaths was highest among the 10–14 age group.

In 2005, 2.9 of every 100,000 people 0–19 years of age were found to have cancer of the brain or central nervous system, and 0.7 per 100,000 died from it. These cancers were found most often in children between 1 and 4 years of age, but the most deaths occurred among those aged 5–9. The main subtypes of brain and central nervous system tumors in children are: astrocytoma, brain stem glioma, craniopharyngioma, desmoplastic infantile ganglioglioma, ependymoma, high-grade glioma, medulloblastoma and atypical teratoid rhabdoid tumor.

Other, less common childhood cancer types are:

- Neuroblastoma (6%, nervous system)

- Wilms tumor (5%, kidney)

- Non-Hodgkin lymphoma (4%, blood)

- Childhood rhabdomyosarcoma (3%, many sites)

- Retinoblastoma (3%, eye)

- Osteosarcoma (3%, bone cancer)

- Ewing sarcoma (1%, many sites)

- Germ cell tumors (5%, many sites)

- Pleuropulmonary blastoma (lung or pleural cavity)

- Hepatoblastoma and hepatocellular carcinoma (liver cancer)

Initially, nearby lymph nodes are struck early. The lungs, liver, brain, and bones are the most common metastasis locations from solid tumors.

- In lymph nodes, a common symptom is lymphadenopathy

- Lungs: cough, hemoptysis and dyspnea (shortness of breath)

- Liver: hepatomegaly (enlarged liver), nausea and jaundice

- Bones: bone pain, fracture of affected bones

- Brain: neurological symptoms such as headaches, seizures, and vertigo

Although advanced cancer may cause pain, it is often not the first symptom.

Some patients, however, do not show any symptoms.

When the organ gets a metastatic disease it begins to shrink until its lymph nodes burst, or undergo lysis.

Throat cancer usually begins with symptoms that seem harmless enough, like an enlarged lymph node on the outside of the neck, a sore throat or a hoarse sounding voice. However, in the case of throat cancer, these conditions may persist and become chronic. There may be a lump or a sore in the throat or neck that does not heal or go away. There may be difficult or painful swallowing. Speaking may become difficult. There may be a persistent earache. Other possible but less common symptoms include some numbness or paralysis of the face muscles.

Presenting symptoms include :

- Mass in the neck

- Neck pain

- Bleeding from the mouth

- Sinus congestion, especially with nasopharyngeal carcinoma

- Bad breath

- Sore tongue

- Painless ulcer or sores in the mouth that do not heal

- White, red or dark patches in the mouth that will not go away

- Earache

- Unusual bleeding or numbness in the mouth

- Lump in the lip, mouth or gums

- Enlarged lymph glands in the neck

- Slurring of speech (if the cancer is affecting the tongue)

- Hoarse voice which persists for more than six weeks

- Sore throat which persists for more than six weeks

- Difficulty swallowing food

- Change in diet or weight loss

Lymphoma is the most common form of cancer in cats, which is often associated with feline leukemia virus, and accounts for 25 percent of all cases. Feline lymphoma usually strikes the digestive system, causing excessive vomiting and diarrhea. Other common symptoms of lymphoma in cats include swollen lymph nodes, loss of appetite, weight loss, and difficulty breathing.

While each type of cancer has its own distinctive symptoms, most of them can indicate their presence by the occurrence and the prolonged presence of any common symptom. Some of the general symptoms of cancer in cats are:

- Any lump that changes shape or size

- Any sore that does not heal

- Change in bowel or bladder habits

- Difficulty eating or swallowing

- Difficulty urinating or defecating

- Unexplained bleeding or discharge from body

- Loss of appetite

- Chronic weight loss

- Coughing or difficulty breathing

- Stiffness

- Oral odor

Note that ravenous hunger, while a sign of other diseases like hyperthyroid, can also be a sign of cancer.

Squamous cell cancers are common in the mouth, including the inner lip, tongue, floor of mouth, gingivae, and hard palate. Cancers of the mouth are strongly associated with tobacco use, especially use of chewing tobacco or "dip", as well as heavy alcohol use. Cancers of this region, particularly the tongue, are more frequently treated with surgery than are other head and neck cancers.

Surgeries for oral cancers include

- Maxillectomy (can be done with or without orbital exenteration)

- Mandibulectomy (removal of the mandible or lower jaw or part of it)

- Glossectomy (tongue removal, can be total, hemi or partial)

- Radical neck dissection

- Mohs procedure

- Combinational e.g., glossectomy and laryngectomy done together.

The defect is typically covered/improved by using another part of the body and/or skin grafts and/or wearing a prosthesis.

Cancer of unknown primary origin (CUP, "occult cancer") is a cancer that is determined to be at the metastatic stage at the time of diagnosis, but a primary tumor cannot be identified. A diagnosis of CUP requires a clinical picture consistent with metastatic disease and one or more biopsy results inconsistent with a primary tumor.

CUP is found in about 3 to 5% of all people diagnosed with invasive cancer, and carries a poor prognosis in most (80 to 85%) of those circumstances. The other 15 to 20% of patients, however, have a relatively long survival with appropriate treatment.

In its early stages, it can go unnoticed. It can be painless with slight physical changes. But the precursor tissue changes, can be noticed by the doctors.

Early stage symptoms can include persistent red or white patches, a non-healing ulcer, progressive swelling or enlargement, unusual surface changes, sudden tooth mobility without apparent cause, unusual oral bleeding or epitaxis and prolonged hoarseness.

Late stage symptoms can include an indurated area, paresthesia or dysesthesia of the tongue or lips, airway obstruction, chronic serous otitis media, otalgia, trismus, dysphagia, cervical lymphadenopathy, persistent pain or referred pain and altered vision.

Around 95% of penile cancers are squamous cell carcinomas. They are classified into the following types:

- basaloid (4%)

- warty (6%)

- mixed warty-basaloid (17%)

- verrucous (8%)

- papillary (7%)

- other SCC mixed (7%)

- sarcomatoid carcinomas (1%)

- not otherwise specified (49%)

Other types of carcinomas are rare and may include small cell, Merkel cell, clear cell, sebaceous cell or basal cell tumors. Non-epithelial malignancies such as melanomas and sarcomas are even more rare.