Anal Pap smears similar to those used in cervical cancer screening have been studied for early detection of anal cancer in high-risk individuals. In 2011, the HIV clinic implemented a program to enhance access to anal cancer screening for HIV-positive men. Nurse practitioners perform anal Papanicolaou screening, and men with abnormal results receive further evaluation with high-resolution anoscopy. The program has helped identify many precancerous growths, allowing them to be safely removed.

Since many, if not most, anal cancers derive from HPV infections, and since the HPV vaccine before exposure to HPV prevents infection by some strains of the virus and has been shown to reduce the incidence of potentially precancerous lesions, scientists surmise that HPV vaccination may reduce the incidence of anal cancer.

On 22 December 2010, the U.S. Food and Drug Administration approved Gardasil vaccine to prevent anal cancer and pre-cancerous lesions in males and females aged 9 to 26 years. The vaccine has been used before to help prevent cervical, vulvar, and vaginal cancer, and associated lesions caused by HPV types 6, 11, 16, and 18 in women.

The diagnosis of urachal cancer can be difficult and usually requires a multidisciplinary approach. A calcification in the midline can be detected in some patients in abdominal imaging studies. A cystoscopy is helpful in most cases. For diagnosis evaluation of a tissue biopsy is needed, which is usually obtained by transurethral resection (TURBT). Measurement of serum concentrations of CEA, CA19-9 and CA125 can be helpful in monitoring urachal cancer

The US Preventive Services Task Force (USPSTF) in 2013 stated evidence was insufficient to determine the balance of benefits and harms of screening for oral cancer in adults without symptoms by primary care providers. The American Academy of Family Physicians comes to similar conclusions while the American Cancer Society recommends that adults over 20 years who have periodic health examinations should have the oral cavity examined for cancer. The American Dental Association recommends that providers remain alert for signs of cancer during routine examinations.

There are a variety of screening devices, however, there is no evidence that routine use of these devices in general dental practice is helpful. However, there are compelling reasons to be concerned about the risk of harm this device may cause if routinely used in general practice. Such harms include false positives, unnecessary surgical biopsies and a financial burden on the patient.

Early diagnosis of oral cancer patients would decrease mortality and help to improve treatment. Oral surgeons and dentists can diagnose these patients in the early stages. Health providers, dentists, and oral surgeons shall have high knowledge and awareness that would help them to provide better diagnosis for oral cancer patients. An examination of the mouth by the health care provider, dentist, oral surgeons shows a visible and/or palpable (can be felt) lesion of the lip, tongue, or other mouth area. The lateral/ventral sides of the tongue are the most common sites for intraoral SCC. As the tumor enlarges, it may become an ulcer and bleed. Speech/talking difficulties, chewing problems, or swallowing difficulties may develop. A feeding tube is often necessary to maintain adequate nutrition. This can sometimes become permanent as eating difficulties can include the inability to swallow even a sip of water. The doctor can order some special investigations which may include a chest x-ray, CT or MRI scans, and tissue biopsy.

While a dentist, physician or other health professional may suspect a particular lesion is malignant, there is no way to tell by looking alone - since benign and malignant lesions may look identical to the eye. A non-invasive brush biopsy (BrushTest) can be performed to rule out the presence of dysplasia (pre-cancer) and cancer on areas of the mouth that exhibit an unexplained color variation or lesion. The only definitive method for determining if cancerous or precancerous cells are present is through biopsy and microscopic evaluation of the cells in the removed sample. A tissue biopsy, whether of the tongue or other oral tissues and microscopic examination of the lesion confirm the diagnosis of oral cancer or precancer.

Urachal cancer usually is an adenocarcinoma (about 90%) mostly with mucinous/colloidal histology. The histology can be difficult to distinguish especially from colorectal cancer and primary adenocarcinoma of the urinary bladder. Immunohistochemistry in this situation is of little help with stains for betaCatenin and Cytokeratin 7 can be helpful. Other rare types include urothelial carcinoma, squamous cell carcinoma, neuroendocrine carcinoma and sarcoma.

Diagnostic systems in use are the Sheldon system based on proposals from Wheeler and Hill and Mostofi. Recent diagnostic classification schemes have been proposed by Herr et al and Gopalan et al. For non-adenocarcinoma urachal cancer a diagnostic classification scheme has been proposed by Paner et al.

The differential for OSSN includes pterygium, pingueculum, papilloma, solar keratosis, lipoma, lymphoma, chronic blepharoconjunctivitis, inflammation, melanoma, ocular pannus, pyogenic granuloma, kaposi sarcoma, keratocanthoma, mucoepidermoid carcinoma, pseudoepitheliomatous hyperplasia, and adenocarcinoma. While confocal microscopy can be used for diagnosis, biopsy is considered the standard, especially before treatment with a cytotoxic medication.

Following a visual examination and a dermatoscopic exam, or "in vivo" diagnostic tools such as a confocal microscope, the doctor may biopsy the suspicious mole. A skin biopsy performed under local anesthesia is often required to assist in making or confirming the diagnosis and in defining severity. Elliptical excisional biopsies may remove the tumor, followed by histological analysis and Breslow scoring. Incisional biopsies such as punch biopsies are usually contraindicated in suspected melanomas, because of the possibility of sampling error or local implantation causing misestimation of tumour thickness. However, fears that such biopsies may increase the risk of metastatic disease seem unfounded.

Total body photography, which involves photographic documentation of as much body surface as possible, is often used during follow-up for high-risk patients. The technique has been reported to enable early detection and provides a cost-effective approach (with any digital camera), but its efficacy has been questioned due to its inability to detect macroscopic changes. The diagnosis method should be used in conjunction with (and not as a replacement for) dermoscopic imaging, with a combination of both methods appearing to give extremely high rates of detection.

This form of cancer is often seen in those who chew tobacco or use snuff orally, so much so that it is sometimes referred to as "Snuff dipper's cancer." Chewing betel nuts is an additional risk factor commonly seen in Taiwan.

Lactate dehydrogenase (LDH) tests are often used to screen for metastases, although many patients with metastases (even end-stage) have a normal LDH; extraordinarily high LDH often indicates metastatic spread of the disease to the liver.

It is common for patients diagnosed with melanoma to have chest X-rays and an LDH test, and in some cases CT, MRI, PET and/or PET/CT scans. Although controversial, sentinel lymph node biopsies and examination of the lymph nodes are also performed in patients to assess spread to the lymph nodes. A diagnosis of melanoma is supported by the presence of the S-100 protein marker.

HMB-45 is a monoclonal antibody that reacts against an antigen present in melanocytic tumors such as melanomas. It is used in anatomic pathology as a marker for such tumors. The antibody was generated to an extract of melanoma. It reacts positively against melanocytic tumors but not other tumors, thus demonstrating specificity and sensitivity. The antibody also reacts positively against junctional nevus cells but not intradermal nevi, and against fetal melanocytes but not normal adult melanocytes.

HMB-45 is nonreactive with almost all non-melanoma human malignancies, with the exception of rare tumors showing evidence of melanogenesis (e.g., pigmented schwannoma, clear cell sarcoma) or tumors associated with tuberous sclerosis complex (angiomyolipoma and lymphangiomyoma).

Depending on several factors and the location of the infection, CIN can start in any of the three stage, and can either progress, or regress. The grade of squamous intraepithelial lesion can vary.

CIN is classified in grades:

Surgical excision or laser therapy are possible treatments. Surgical excision alone was effective for controlling VC, but elective neck dissection was not necessary even in patients in the advanced stages.

Treatment for CIN 1, which is mild dysplasia, is not recommended if it lasts fewer than 2 years. Usually when a biopsy detects CIN 1 the woman has an HPV infection which may clear on its own within 12 months, and thus it is instead followed for later testing rather than treated.

Treatment for higher grade CIN involves removal or destruction of the neoplastic cervical cells by cryocautery, electrocautery, laser cautery, loop electrical excision procedure (LEEP), or cervical conization. Therapeutic vaccines are currently undergoing clinical trials. The lifetime recurrence rate of CIN is about 20%, but it isn't clear what proportion of these cases are new infections rather than recurrences of the original infection.

Surgical treatment of CIN lesions is associated with an increased risk of infertility or subfertility, with an odds ratio of approximately 2 according to a case-control study.

The treatment of CIN during pregnancy increases the risk of premature birth.

Most conjunctival squamous cell carcinomas are removed with surgery. A few selected cases are treated with topical medication. Surgical excision with a free margin of healthy tissue is a frequent treatment modality. Radiotherapy, given as external beam radiotherapy or as brachytherapy (internal radiotherapy), can also be used to treat squamous cell carcinomas.

HPV+OPC is usually diagnosed at a more advanced stage than HPV-OPC, with 75–90% having involvement of regional lymph nodes. Genetic signatures of HPV+ and HPV- OPC are different. HPV+OPC is associated with expression level of the E6/E7 mRNAs and of p16. Nonkeratinizing squamous cell carcinoma strongly predicts HPV-association. HPV16 E6/E7-positive cases are histopathologically characterized by their verrucous or papillary (nipple like) structure and koilocytosis of the adjacent mucosa. Approximately 15% of HNSCCs are caused by HPV16 infection and the subsequent constitutive expression of E6 and E7, and some HPV-initiated tumors may lose their original characteristics during tumor progression. High-risk HPV types may be associated with oral carcinoma, by cell-cycle control dysregulation, contributing to oral carcinogenesis and the overexpression of mdm2, p27 and cathepsin B.

HPV+OPC is not merely characterized by the presence of HPV-16. Only the expression of viral oncogenes within the tumor cells plus the serum presence of E6 or E7 antibodies is unambiguously conclusive. There is not a standard HPV testing method in head and neck cancers, both in situ hybridization (ISH) and polymerase chain reaction (PCR) are commonly used. Both methods have comparable performance for HPV detection, however it is important to use appropriate sensitivity controls. Immunohistochemistry (IHC) staining of the tissue for p16 is frequently used as a cost effective surrogate for HPV in OPC, compared to ISH or PCR but there is a small incidence of HPV-negative p16-positive disease accounting for about 5% of HPV-OPC.

Basal-cell carcinoma is a common skin cancer and occurs mainly in fair-skinned patients with a family history of this cancer. Sunlight is a factor in about two-thirds of these cancers; therefore, doctors recommend sunscreens with at least SPF 30. One-third occur in non-sun-exposed areas; thus, the pathogenesis is more complex than UV exposure as "the" cause.

The use of a chemotherapeutic agent such as 5-Fluorouracil or imiquimod, can prevent development of skin cancer. It is usually recommended to individuals with extensive sun damage, history of multiple skin cancers, or rudimentary forms of cancer (i.e., solar keratosis). It is often repeated every 2 to 3 years to further decrease the risk of skin cancer.

The following methods are employed in the treatment of basal-cell carcinoma (BCC):

The presence of HPV within the tumour has been realised to be an important factor for predicting survival since the 1990s. Tumor HPV status is strongly associated with positive therapeutic response and survival compared with HPV-negative cancer, independent of the treatment modality chosen and even after adjustment for stage. While HPV+OPC patients have a number of favourable demographic features compared to HPV-OPC patients, such differences account for only about ten per cent of the survival difference seen between the two groups. Response rates of over 80% are reported in HPV+ cancer and three-year progression free survival has been reported as 75–82% and 45–57%, respectively, for HPV+ and HPV- cancer, and improving over increasing time. It is likely that HPV+OPC is inherently less maligant than HPV-OPC, since patients treated by surgery alone have a better survival after adjustment for stage. In one study, less than 50% of patients with HPV-OPC were still alive after five years, compared to more than 70% with HPV+OPC and an equivalent stage and disease burden.

In RTOG clinical trial 0129, in which all patients with advanced disease received radiation and chemotherapy, a retrospective analysis (recursive-partitioning analysis, or RPA) at three years identified three risk groups for survival (low, intermediate, and high) based on HPV status, smoking, T stage and N stage ("see" Ang et al., Fig. 2). HPV status was the major determinant of survival, followed by smoking history and stage. 64% were HPV+ and all were in the low and intermediate risk group, with all non-smoking HPV+ patients in the low risk group. 82% of the HPV+ patients were alive at three years compared to 57% of the HPV- patients, a 58% reduction in the risk of death. Locoregional failure is also lower in HPV+, being 14% compared to 35% for HPV-. HPV positivity confers a 50–60% lower risk of disease progression and death, but the use of tobacco is an independently negative prognostic factor. A pooled analysis of HPV+OPC and HPV-OPC patients with disease progression in RTOG trials 0129 and 0522 showed that although less HPV+OPC experienced disease progression (23 v. 40%), the median time to disease progression following treatment was similar (8 months). The majority (65%) of recurrences in both groups occurred within the first year after treatment and were locoregional. HPV+ did not reduce the rate of metastases (about 45% of patients experiencing progression), which are predominantly to the lungs (70%), although some studies have reported a lower rate. with 3-year distant recurrence rates of about 10% for patients treated with primary radiation or chemoradiation. Even if recurrence or metastases occur, HPV positivity still confers an advantage.

By contrast tobacco usage is an independently negative prognostic factor, with decreased response to therapy, increased disease recurrence rates and decreased survival. The negative effects of smoking, increases with amount smoked, particularly

if greater than 10 pack-years. For patients such as those treated on RTOG 0129 with primary chemoradiation, detailed nomograms have been derived from that dataset combined with RTOG 0522, enabling prediction of outcome based on a large number of variables. For instance, a 71 year old married non-smoking high school graduate with a performance status (PS) of 0, and no weight loss or anaemia and a T3N1 HPV+OPC would expect to have a progression-free survival of 92% at 2 years and 88% at 5 years. A 60 year old unmarried nonsmoking high school graduate with a PS of 1, weight loss and anaemia and a T4N2 HPV+OPC would expect to have a survival of 70% at two years and 48% at five years. Less detailed information is available for those treated primarily with surgery, for whom less patients are available, as well as low rates of recurrence (7–10%), but features that have traditionally been useful in predicting prognosis in other head and neck cancers, appear to be less useful in HPV+OPC. These patients are frequently stratified into three risk groups:

- Low risk: No adverse pathological features

- Intermediate risk: T3–T4 primary, perineural or lymphovascular invasion, N2 (AJCC 7)

- High risk: Positive margins, ECE

HPV+OPC patients are less likely to develop other cancers, compared to other head and neck cancer patients. A possible explanation for the favourable impact of HPV+ is "the lower probability of occurrence of 11q13 gene amplification, which is considered to be a factor underlying faster and more frequent recurrence of the disease" Presence of TP53 mutations, a marker for HPV- OPC, is associated with worse prognosis. High grade of p16 staining is thought to be better than HPV PCR analysis in predicting radiotherapy response.

Anal sac adenocarcinomas are often suspected due to location (palpable masse in anal sac) and behavior, but a biopsy and histopathology is necessary for a definitive diagnosis. Fine needle aspiration and cytology is a common first step. Cytopathology reveals clusters of cells with uniform round nuclei. These cells do not have many of the features usually associated with malignancy, such as a high nucleus to cytoplasm ratio or prominent nucleoli. Ultrasonography and radiography are performed to look for metastasis.

An important anatomic landmark in anal cancer is the pectinate line (dentate line), which is located about 1–2 cm from the anal verge (where the anal mucosa of the anal canal becomes skin). Anal cancers located above this line (towards the head) are more likely to be carcinomas, whilst those located below (towards the feet) are more likely to be squamous cell carcinomas that may ulcerate. Anal cancer is strongly associated with ulcerative colitis and the sexually transmissible infections HPV and HIV. Anal cancer may be a cause of constipation or tenesmus, or may be felt as a palpable mass, although it may occasionally present as an ulcerative form.

Anal cancer is investigated by biopsy and may be treated by excision and radiotherapy, or with external beam radiotherapy and adjunctive chemotherapy. The five-year survival rate with the latter procedure is above 70%.

Aggressive surgical removal of the tumor and any enlarged sublumbar lymph nodes is essential for treatment of the tumor and associated hypercalcaemia. There is a high recurrence rate, although removal of lymph nodes with metastasis may improve survival time. Radiation therapy and chemotherapy may be helpful in treatment. Severe hypercalcaemia is treated with aggressive IV fluid therapy using sodium chloride and medications such as loop diuretics (increased kidney excretion of calcium) and aminobisphosphonates (decreased calcium release from bones). A poorer prognosis is associated with large tumor size (greater than 10 cm), hypercalcaemia, and distante metastasis. Early, incidental diagnosis of small anal sac masses may lead to a better prognosis with surgery alone (ongoing study).

Colorectal cancer is a disease of old age: It typically originates in the secretory cells lining the gut, and risk factors include diets low in vegetable fibre and high in fat. If a younger person gets such a cancer, it is often associated with hereditary syndromes like Peutz-Jegher's, hereditary nonpolyposis colorectal cancer or familial adenomatous polyposis. Colorectal cancer can be detected through the bleeding of a polyp, colicky bowel pain, a bowel obstruction or the biopsy of a polyp at a screening colonoscopy. A constant feeling of having to go to the toilet or anemia might also point to this kind of cancer.

Use of a colonoscope can find these cancers, and a biopsy can reveal the extent of the involvement of the bowel wall. Removal of a section of the colon is necessary for treatment, with or without chemotherapy. Colorectal cancer has a comparatively good prognosis when detected early.

First dilemma in diagnosis is recognition. As lentigo malignas often present on severely sun-damaged skin, it is frequently found amongst numerous pigmented lesions – thin seborrheic keratoses, lentigo senilis, lentigines. It is difficult to distinguish these lesions with the naked eye alone, and even with some difficulty using dermatoscopy. As the lentigo maligna is often very large, it often merges with, or encompasses other skin tumors – such as lentigines, melanocytic nevi, and seborrheic keratosis.

Second dilemma is the biopsy technique. Even though excisional biopsy (removing the entire lesion) is ideal, and advocated by pathologists; practical reason dictates that this should not be done. These tumors are often large and presenting on the facial area. Excision of such large tumor would be absolutely contraindicated if the lesion's identity is uncertain. The preferred method of diagnosis is by using a punch biopsy, allowing the physician to sample multiple full thickness pieces of the tumor at multiple sites. While one section of the tumor might show benign melanocytic nevus, another section might show features concerning for severe cellular atypia. When cellular atypia is noted, a pathologist might indicate that the entire lesion should be removed. It is at this point that one can comfortablly remove the entire lesion, and thus confirm the final diagnosis of lentigo maligna. The size of the punch biopsy can vary from 1 mm to 2 mm, but it is preferable to use a punch 1.5 mm or larger. Representative samples of the most atypical parts of the nevus should be biopsied, often guided by dermatoscopy.

Since 80% of grey horses will develop a melanoma tumor at some point in their lives, it is important to know what kind of treatments are available. There are several treatment options when a horse is found to have a melanoma tumor including surgical or injections:

Even though the ideal method of diagnosis of melanoma should be complete excisional biopsy, the location of the melanoma may require alternatives. Dermatoscopy of acral pigmented lesions is very difficult but can be accomplished with diligent attention. Initial confirmation of the suspicion can be done with a small wedge biopsy or small punch biopsy. Thin deep wedge biopsies can heal very well on acral skin, and small punch biopsies can give enough clue to the malignant nature of the lesion. Once this confirmatory biopsy is done, a second complete excisional skin biopsy can be performed with a narrow surgical margin (1 mm). This second biopsy will determine the depth and invasiveness of the melanoma, and will help to define what the final treatment will be. If the melanoma involves the nail fold and the nail bed, complete excision of the nail unit might be required. Final treatment might require wider excision (margins of 0.5 cm or more), digital amputation, lymphangiogram with lymph node dissection, or chemotherapy.