How do doctors determine what stage of cancer you have? - Hyunsoo Joshua No and Trudy Wu

翻译人员: Tong PL 校对人员: Gia Hwang

Each year, approximately 20 million people across the world

每年，全球约有 2000 万人

receive a cancer diagnosis.

接受癌症诊断。

At this overwhelming, and often scary time,

在这个令人不知所措 且常常令人恐惧的时刻，

a patient usually learns their cancer’s stage,

患者一般上会得知他们癌症的分期，

which is typically a number, ranging from 1 to 4.

通常是一个 1-4 的数字。

While staging is designed in part to help patients better understand

虽然分期的设计部分是 为了帮助患者更好地了解

what they’re facing,

他们所面临的情况，

extracting this information from a simple number

但要从一个简单的数字中提取这些信息

can be confusing and less than straightforward.

可能会令人困惑且并非简单直接。

So, what do cancer stages actually mean?

那么，癌症分期的意义到底是什么呢？

To understand stage numbers,

要想了解这些分期数字的含义，

we first need to unpack the three variables that inform it.

我们首先需要解析决定分期的三个变量。

Doctors utilize a system which uses the letters T, N, and M

医生们运用一个使用 字母 T、N 和 M 的系统

to describe a tumor’s size,

来描述肿瘤的大小、

its presence in the immune system’s lymph nodes,

它在免疫系统淋巴结中的存在

and whether it has metastasized, or spread, to other organs.

以及是否已经转移或扩散到其他器官。

Arriving at this letter staging takes thorough investigation—

得出这种字母分期需要彻底的调查——

physicians will consider a person’s symptoms and overall health,

医生会将一个人的症状 和整体健康状况纳入考量，

and may sample, or biopsy, cancerous tissue,

还可能对癌组织进行采样或活检，

order medical scans, and analyze blood tests.

进行医学扫描，并分析血液检查结果。

The T designation is usually a number between 1 to 4,

T 的分期通常是 介于 1 到 4 之间的数字，

and is, in most cases, based on tumor size.

并在大多数情况下基于肿瘤的大小。

But each type of cancer has its own T staging criteria.

但是每种类型的癌症 都有自己的 T 分期标准。

Five-centimeter-wide tumors are labeled as T3 in oral cancers,

五厘米宽的肿瘤 在口腔癌中被标记为 T3 ，

but T2 in breast cancers.

但在乳腺癌中被标记为 T2 。

And some cancers use other staging criteria,

还有一些癌症使用其他的分期标准，

like esophageal cancers, which are staged based on how deeply

例如食道癌是根据肿瘤入侵组织层的深度

the tumor invades the layers of tissue.

来进行分期的。

To assign an N stage,

为确认 N 期，

doctors evaluate the lymph nodes through biopsies and imaging.

医生通过活检和影像对淋巴结进行评估。

Cancer cells tend to break off from the initial tumor and spread.

癌细胞往往会从最初的肿瘤中 分离出来并扩散。

They often travel through the lymphatic system—

它们经常穿过淋巴系统——

a network of vessels and nodes,

一个由血管和淋巴结组成的系统，

which filter waste and harbor cells that help fight infection.

用于过滤废物并储存 有助于抵抗感染的细胞。

Cancers that spread to larger, more distant,

扩散到更大、更远或更多淋巴结的癌症，

or a greater number of lymph nodes typically file into higher N stages.

N 通常会界定为更高等级的数字。

M staging involves a more threatening category of cancers’ spread—

M 分期涉及一种 更具威胁性的癌症扩散，

when diseased cells scatter and then settle on other organs or on bones.

即患病细胞扩散到其他器官或骨头上。

Historically, this stage has been a matter of just “yes” or “no,”

历史上，这一分期只是一个 “是” 或 “否” 的问题，

because once a cancer has metastasized, it’s considered to be much more lethal.

因为癌症一旦转移， 就会被认为具有更大的致命性。

But advances in treatment have recently prompted the medical community

但近年来癌症治疗的进展促使医学界

to rethink the M stage as a continuum.

重新考虑将 M 期 视为一个连续的状态。

Doctors now consider the number of organs in which the cancer has spread,

现在，医生会将癌症扩散的器官数量

as well as the abundance and characteristics of the metastatic tumors.

以及转移性肿瘤的数量和特征纳入考量。

All sorts of combinations of T, N, and M are possible,

T、N 和 M 的各种组合都有可能，

and one letter doesn't always follow the other.

且一个字母并不总是紧随另一个字母。

For example, some head and neck cancers will test positive in the lymph nodes N1

例如，一些头部与颈部癌症的 淋巴结 N1 检测结果呈阳性，

with no clear initial tumor, or T0.

但没有明显的初始肿瘤， 即 T0 。

So how do these three variables inform a cancer's stage number?

那么，这三个变量如何 决定癌症的分期呢？

Each TNM combination correlates to a different overall stage,

按照癌症治疗的难度排列，

ordered by how difficult the cancer is to treat.

每种 TNM 组合都对应着 不同的总体分期。

This sorting is rigidly defined for each type of cancer,

这种分类方式是根据 各种类型的癌症严格制定的，

based on generations of research looking at how cancers with different spreads

基于几代人对于不同的癌症扩散方式

and characteristics tend to behave.

与行为特征的研究。

Importantly, what a certain overall stage means varies from cancer to cancer.

重要的是，某个总体分期的含义 因癌症种类而异。

For example, a T3N1M0 combination for a breast cancer

例如，乳腺癌的 T3N1M0 组合

is considered stage 3 and carries an 85% five-year survival rate.

被视为癌症三期， 五年存活率为 85% 。

A pancreatic cancer with this same TNM combination, however,

但是，具有相同 TNM 组合的胰腺癌

is sorted to stage 2, and yet is more difficult to treat

被分为癌症二期，但治疗更加困难，

with a 15% survival rate.

存活率仅有 15 ％ 。

The system is intricate— and ever-changing.

这系统错综复杂，而且不断变化。

For instance, someone with a stage 4 throat tumor in 2017,

例如， 2017 年患有四期喉部肿瘤的人

might be considered stage 1 just one year later.

在一年后可能仅被视为一期。

The cancer didn’t improve; the staging system did.

癌症并没有改善，只是分期系统改了。

Experts realized that a subset of these advanced cancers

专家们发现，部分晚期癌症

responded to existing treatment better than others,

对于现有治疗方案的反应 要好于其他癌症，

so their staging was downgraded.

因此它们的分期被降级。

Similar discoveries and advancements in the genetic testing of tumors

肿瘤基因检测方面相似的发现和进展

are refining staging in breast, prostate, and gynecological cancers.

正在完善乳腺癌、前列腺癌 和妇科癌的分期。

Meanwhile, breakthroughs in therapies can change things seemingly overnight.

同时，疗法的突破似乎可以 在一夜之间改变现状。

Many cancers one considered near impossible to treat

许多被认为几乎不可能治愈的癌症，

are now met with high rates of remission.

现在的缓解率很高。

And thanks to improvements in screenings,

而且，由于筛查技术的改进，

more and more cancers are being discovered at early stages.

越来越多的癌症在早期就被发现。

So while many will deal with the reality of cancer,

因此，尽管许多人将要面对癌症的现实，

either for themselves, or through the diagnosis of a loved one,

无论是亲身面对还是通过亲人的诊断，

these advances offer better treatments, more targeted cures,

这些进步提供了更好的治疗方法、 更针对性的治愈方案，

and greater hope for the years to come.

为未来带来了更大的希望。