Often, cancers are characterized by their abrupt occurrence. However, most
cancers originate earlier and gradually develop in the subclinical stage.
Even though this development varies from organ to organ, it may also differ
for each patient. Hence, individualizing patients in terms of effective
therapy and the early detection of cancer is imperative. Furthermore, the
prevention of cancer is essential to avoid its proliferation.
Surgical pathologists are expected to provide a definitive diagnosis of
cancer and precisely assess the biological behavior of each patient.
However, the accurate diagnosis of precancerous lesions and the precise
assessment of the possibility and their progression rate into clinically
significant cancer will be spectacular, rendering the precancerous stage as
entirely curable.
Apparently, the pathological diagnosis of all precancerous stages is
complicated, as not all stages are morphologically evident. However, we
may be able to detect precancerous “lesions.” On the basis of the organs
and/or histological types, the concept and term of these lesions vary,
including dysplasia (i.e., uterine cervix), atypical hyperplasia (i.e.,
endometrium), adenoma (i.e., colorectum), intraepithelial neoplasia, or
intraepithelial lesion. Occasionally, intraductal (noninvasive) carcinomas
may also be included, as these are non-lethal and their distinction from
dysplasia is complicated.
The primary feature of precancerous lesions is their potential to
progress into definite (invasive) cancer in future, even though the
possibility and their progression rates vary, leading to the use of the terms
“borderline lesions,” “borderline malignancy,” or “atypically proliferating
lesions” in some organs (e.g., ovary). Although benign and malignant tumors
may possess a middle degree of atypia, their biological behavior (early stage
and the possibility of progression) may not be necessarily considered. At
times, the same technical term may be used differently; for example,
atypical hyperplasia in the breast signifies risk lesions rather than real
precursors, and adenomas in various organs are entirely benign that will
not progress into adenocarcinoma. Furthermore, several cancers may not
have precursors and directly originate from healthy tissues (de novo
cancer).
This textbook intends to elucidate the current standards and novel
knowledge regarding carcinogenesis, molecular features, histopathological diagnosis, and the clinical significance of precancerous and early-stage
female cancers such as breast, ovarian, and uterine carcinomas. Apparently,
the pathways of cancer development significantly vary among organs, with
heterogeneous precursors and early lesions based on the histological type
of cancer in the same organ. Recently, several paradigm shifts have been
advocated in these areas, for examples, the underlying mechanism of highgrade serous carcinoma of the ovary (and the peritoneum). It may be
reckoned that the recognition of the current concept will lead to the most
appropriate approach for the diagnosis, treatment, and patient care.
As readers of this book may be familiar with the variegated development
of these cancers, this book comprises eight chapters, including two chapters
focusing on uterine cervical (precursors of squamous cell carcinoma and
adenocarcinoma), one on endometrial (heterogeneity of precursors), three
on ovarian (two pathways of carcinogenesis and the significance of
borderline tumors), and two on mammary (significance of intrinsic subtype
and risk assessment for non-cancerous lesions) cancers.
All contributors to this book are exceptional Japanese surgical
pathologists. Although each chapter in this book puts forth global
perspectives, it also presents Japanese perspective in some parts. I hope
that this book serves as a useful reference for grasping the advanced
knowledge and facilitate the daily practice of pathologists, gynecologists,
breast surgeons, and all medical staff members in these fields.