The goal of this study is to show that trained detection dogs can identify breast, lung, prostate or colorectal cancer by sniffing masks containing breath samples. In this study, individuals who will undergo cancer screening at an integrated cancer prevention center or biopsy for a suspected malignancy, will be asked to provide a breath sample by breathing into a surgical mask. The mask will then be sent to the laboratory, where trained detection dogs will determine if the person who provided the mask has breast, lung, prostate or colorectal cancer or if the person does not have these types of cancer. The results provided by the dogs will be compared to the actual cancer screening results or biopsy results in order to determine the accuracy of cancer detection by the trained dogs.

Inclusion Criteria:

1. Men and women aged 18 and over.
2. Signing an informed consent prior to performing the test.
3. Intended to undergo screening tests for cancer detection.
4. Did not smoke 2 hours before providing the breath sample
5. Did not drink coffee in the hour before providing the breath sample
6. Did not drink an alcoholic beverage in the hour prior to providing the breath sample.
7. Did not eat food in the hour before providing the breath sample.

Exclusion Criteria:

1. Was diagnosed with cancer or was treated for cancer in the seven years preceding the study, excluding non-metastatic skin tumors that were surgically removed.
2. Undergoing chemotherapy for any purpose.
3. Pregnant or breastfeeding
4. Had a medical procedure in the chest cavity and/or airways in the two weeks prior to providing the breath sample that may interfere with the ability to correctly provide a breath sample.
5. Has a Helicobacter pylori infection.
6. Has a peptic ulcer disease.
7. Has a flare-up of an inflammatory bowel disease (Crohn's disease/ulcerative colitis).
8. has an active infection, such as COVID-19, abscess, bacterial/viral/fungal infection, pneumonia, laryngitis, intestinal inflammation, active tuberculosis infection.

Men and women over the age of 18 undergoing screening for early detection of breast cancer, colon cancer, lung cancer, and prostate cancer at the medical centers participating in the study.