Self-breast exam "Self-check of mammal cancer" Let's install the routine of once a month check!


English 乳がん

For an early detection of mammal cancer, you need a screening every two years after your forties. However, some women develop cancer under their thirties... so we recommend to self-check your breasts once a month. It's important to be familiar with your breasts while you are fine, so it's easier to notice if there is any abnormality.

How to self-check breast cancer?


Breast cancer self-checks should be carried out monthly, ideally one week to 10 days after the end of your period when the breasts are not swollen. If you no longer have periods, you can choose a specific day each month like your birth day, it's easier to remember. We suggest to check while taking a shower.

Look! (visualization of your breasts)

When you look at your breasts in the mirror, you have to check if there are no sunken parts like a dimple. when the cancer pulls the skin, a sunken part appears. If you find a sunken part, and you feel a lump at the end of it, it might be a cancer. If you don't feel any lump, don't worry because it might just be some fat.


Touch your breast. Do not grab the skin, because you can feel mammal glands hard, and mistake it for a lump.

Don't grab

Touch gently in a small circle, from the outside to the center, checking the whole breast. You may start where ever you want, but don't forget to check the whole breast. Don't press the breast too much because it can hurt, but you have to press a minimum.
Touching area goes from the clavicle till the end of the curved shape of breast.
As mammal glands continue under the clavicle, it's important to check this area even for elderly women. Some people cannot make a distinction between a bone and a lump, but the peculiarity of a bone is that it's much longer.

To pinch

Let's pinch the nipple gently to check if no blood comes out. Because if there is a cancer, some blood can accumulate in the milk sacs situated at the bottom of the nipple. If blood comes out, it will look like if you have a bleeding nose. Be careful not to pinch too strongly. You could bleed because of it. Besides, you don't need to worry if a transparent liquid comes out.

Important point concerning breast self-checks

Breast self-checks should be carried out monthly, to know "what is normal". In this case, if ever you feel a lump which wasn't there till now, you can easily notice it. As the hardness of the lump isn't the same for everyone, do not think that "a lump is hard like a stone". It's important to know your breast to encounter any abnormality.

What to do in case of any change

If you encounter any change like a sunken part, a lump, bleeding, please have a mammography. However, if you felt a lump before your periods, don't be impatient and wait until the end of your period. Because, as mammal glands before having periods, you could mislead and take it for a cancer. Besides, when mammal glands swell it could be painful, but there is no relation between pain and cancer. If it is only a swelling of mammal glands, it disappears naturally after the end of periods. If not, please have a mammography.

Breast cancer self-checks are not 100% sure

Self-check is just to have an idea of a possible cancer. There are cancers which can't be found by self-checking. There are also women who are more likely to have mammal cancer for genetic reasons.

We recommend you, to use this check-list:

Check-list to know if you are more likely to have breast cancer genetically.

If it indicates that you have "a high risk" to have a breast cancer, we recommend you to see a doctor. For women over 40, please check once every two years.

Check your risk (high-risk or low-risk) to have a breast cancer

Breast cancer screening is usually (in principle) done once every 2 years for women over 40. This is because breast cancer appears rarely when being young but increases dramatically above the age of 40 years old. However, several (some) members of the Japanese Cancer Association recommends to have an examination for women in their twenties or thirties.

Especially for women having a hereditary predisposition to breast cancer. This represents 5 to 10 % of breast cancer patients.
Here are some easy self-check questions for women who are anxious.
You have to check if your relatives had breast cancer / ovarian cancer. This must be checked till third-degree relatives as well as on your father's side.


Hereditary predisposition to breast cancer check-list


 If there are more than 2 persons who got breast cancer on the same branch of relatives.
(If there is one person on each side, don't check)

 The person has developed more than two "first" breast cancer.

 Among persons developing breast cancer, some were less than 45 years old.

 There is a person (male) who has breast cancer among your relatives.

 Some relatives got ovarian cancer.

If you have one of the above indications, you might have a high-risk to develop breast cancer.

We recommend to see a Doctor for further information.